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Here we report a tunable polarization-independent broadband absorber in the terahertz regime. The proposed structure consists of periodic all-dielectric array on a gold substrate, sandwiched by a monolayer graphene and an epsilon-near-zero layer. Simulation results show that the absorption that is independent from the incident polarization remains above 90% over a broadband spectral range from 1.6 THz to 4.1 THz, corresponding to a bandwidth of 2.5 THz and a relative bandwidth of 87.7%. By varying the graphenes Fermi energy from 0.2 eV to 0.5 eV, the absorption bandwidth can be turned from 1.5 THz to 2.5 THz. We expect this polarization- independent absorber with dynamically tunable bandwidth can be used a filters in applications such as terahertz detectors.

Xuejun Qiu,1 Xinru You,2 Xing Chen,2 Haolin Chen,1 Arvind Dhinakar,3 Songhao Liu,1 Zhouyi Guo,1 Jun Wu,2,4 Zhiming Liu1 1SATCM Third Grade Laboratory of Chinese Medicine and Photonics Technology, College of Biophotonics, South China Normal University, 2Guangdong Provincial Key Laboratory of Sensor Technology and Biomedical Instrument, School of Engineering, Sun Yat-Sen University, Guangzhou, Guangdong, People’s Republic of China; 3Faculty of Engineering, University of Waterloo, Waterloo, ON, Canada; 4Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Sun Yat-Sen University, Guangzhou, Guangdong, People’s Republic of China Abstract: The rapid development of near-infrared surface-enhanced Raman scattering (NIR SERS) imaging technology has attracted strong interest from scientists and clinicians due to its narrow spectral bandwidth, low background interference, and deep imaging depth. In this report, the graphene oxide (GO)-wrapped gold nanorods (GO@GNRs) were developed as a smart and robust nanoplatform for ultrafast NIR SERS bioimaging. The fabricated GO@GNRs could efficiently load various NIR probes, and the in vitro evaluation indicated that the nanoplatform could exhibit a higher NIR SERS activity in comparison with traditional gold nanostructures. The GOs were prepared by directly pyrolyzing citric acid for greater convenience, and GO@GNRs were fabricated via a facile synthesis strategy. Higher NIR SERS activity, facile synthesis method, excellent biocompatibility, and superb stability make the GO@GNRs/probe complex promising nanoprobes for NIR SERS-based bioimaging applications. Keywords: gold nanorods, graphene oxide, near-infrared bioimaging, surface-enhanced Raman scattering

The chirality of photons plays a fundamental role in light-matter interactions. However, a limiting factor in photonic integrated circuits is the lack of a miniaturized component, which can distinguish the chirality in a low cost and integrated manner. Herein we numerically demonstrate a chirality-distinguishing beamsplitter that can address this challenge. It consists of an integrated polarization rotator and a linear polarization beamsplitter, which together can fulfill the task of distinguishing and splitting left- and right-handed quasi-circularly polarized modes on a chip with an ultra-broadband operation range from 1.45 μm to 1.65 μm. Owning to the reciprocity, the device can emit photons with selectable spin angular momentum depending on the chosen feeding waveguide. The device is compatible with complementary metal-oxide semiconductor technology and it may open up new avenues in the fields of on-chip nano-photonics, bio-photonics and quantum information science.

A novel full-duplex radio-over-fiber system is proposed and demonstrated, in which an external modulator and an optical interleaver are used to generate dual octupling-frequency optical millimeter waves for two base stations and wavelength reuse for uplink connection. This scheme is simplified and low-cost because no additional laser is utilized for uplink connection at two base stations and one laser at central office works for two base stations simultaneously. The frequency of local oscillator signal is reduced largely due to frequency octupling. The theorem about how to generate optical millimeter waves is analyzed. The simulation results show that the bidirectional 5 Gb/s system has a perfect performance because the power penalty for the downlink and uplink signals of two base stations are less than 0.6 dB after successful transmission over 60 km standard single mode fiber.

Nanoscience is a grand and wide science, and there are many kinds of nanomaterials. In this paper nanomaterials are divided into three: the naturial nanocrystals, the artificial nano structural materials and the functional polymer materials. Carbon nanotechnologies which are in the fast-development areas are reviewed in detail including their structural features, opto-electronic properties and its applications used as optoelectronic devices. And the graphene are introduced in detail. Especially emphasize is put on the the carbon nanotechnology development and its importance.

Objective To observe the clinical effects in the treatment of prostatic hyperplasia by laser radiation on acupoints.

The S parameter expression of high-frequency models of the high electron mobility transistors (HEMTs) with basic feedback structure, especially the transmission gain S21, is presented and analyzed. In addition, an improved feedback structure and its theory are proposed and demonstrated, in order to obtain a better gain-flatness through the mutual interaction between the series inductor and the parallel capacitor in the feedback loop. The optimization solution for the feedback amplifier can eliminate the negative impacts on transmission gain S21 caused by things such as resonance peaks. Furthermore, our theory covers the shortage of conventional feedback amplifiers, to some extent. A wideband low-noise amplifier (LNA) with the improved feedback technology is designed based on HEMT. The transmission gain is about 20 dB with the gain variation of 1.2 dB from 100 MHz to 6 GHz. The noise figure is lower than 2.8 dB in the whole band and the amplifier is unconditionally stable.

Detection efficiency is one of the key parameters that affect the performance of gated-mode avalanche photodiodes in quantum key distribution. In this paper, the impact of the waveform of faint picosecond laser pulses on detection efficiency is investigated both experimentally and analytically. Two kinds of laser pulses are attenuated to the single photon level to measure and plot single photon detection efficiency versus synchronous delay between the detector and the laser source. The results show that the narrower laser pulse with single peak can be detected with about 9% higher detection efficiency and lead to a lower QBER than the pulse with subpeak and a broadened pedestal.

We present implementation of quantum cryptography with polarization code by wave-guide type phase modulator. At four different low input voltages of the phase modulator, coder encodes pulses into four different polarization states, 45°, 135° linearly polarized or right, left circle polarized, while the decoder serves as the complementary polarizers.

In this paper, a novel configuration of reflection L-band erbium-doped fiber amplifier (L-EDFA) via inserting a 980 nm pump laser diode (LD) in the input part was constructed. By selecting appropriate power ratio of the 980 and 1480 nm pump LD, gain and noise figure (NF) of the L-EDFA are greatly improved in different degree in the wavelength region from 1565 to 1615 nm. Compared to the configuration pumped by only 1480 nm pump LD with given power, the noise figure decreases 1.3–9.4 dB and the gain enhances 1.5–9.9 dB.

Modulation instability (MI) to generate femtosecond pulse in dispersion-decreasing fibers (DDF) is investigated. Higher-order dispersion effect and higher-order nonlinear effects are taken into account when continuous wave or quasi-continuous wave evolves into sub-picosecond or femtosecond pulses by MI in optical fibers. Our research results show that the gain spectrum of the DDF is much wider than that in conventional fibers. The third-order dispersion effect has no contribution to gain spectrum, self-steepening effect reduces the maximum value and gain bandwidth of gain spectrum, and Raman self-scattering effect widens the extent where MI occurs.

Single wall carbon nanotubes of tubule diameter 1.0–1.7 nm were synthesized by the irradiation of continuous CO 2 laser (500–900 W) onto a graphite–Co/Ni composite target at room temperature. We suggest that the high temperature plays a unique key role in the growth of single-wall carbon nanotubes in the laser ablation method, while laser wavelength is less important. The transmission electron microscope observations show that the average diameter of single wall carbon nanotubes produced by the CO 2 laser is larger than one produced by YAG laser vaporization, and the tube diameter increases with increasing laser power. We present the Raman spectrum of single-wall carbon nanotubes produced by using CO 2 continuous laser vaporization with laser excitation wavelengths 632.8 and 514.5 nm, and these Raman scattering are compared with those of nanotubes produced by other laser ablation of previous reports.

Differential phase shift quantum key distribution scheme has been improved by introducing a passive path selection structure at the transmitter including two polarization controllers used to mark the photon pulses and a polarizing beam splitter to distinguish these pulses so that can make different time delay at the receiver. Theoretical analysis indicates that a free-space-based differential phase shift quantum key distribution system with this proposed improvement will have high efficiency with the utilization ratio of photons reaching 100% under ideal condition.

Photobiomodulation (PBM) is a biomedical treatment that uses monochromatic light or laser irradiation to stimulate or inhibit biological functions. Therapeutic applications of PBM are very common in China as the research on PBM and its therapeutic applications are very advanced. This paper reviews the literature in terms of the function-specific homeostasis, genetic redundancy and self-adaptation of the PBM phenomena and gives an overview of the clinical applications, such as laser acupuncture, intravascular low energy laser therapy, intranasal low intensity laser therapy and laser surgery, taking into consideration the approaches of functional medicine and Traditional Chinese Medicine.

Chirped gratings with uniform Kerr nonlinearity are numerically demonstrated to have direction-dependent switching behavior, which is caused by the different energy storage between the two incident directions. This effect can find useful applications such as optical diode and optical switch-isolator.

Laser has been used clinically as a therapeutic tool for at least twenty years and has achieved good clinical results. An understanding of optical properties of tissue is important for these applications. However, applying the rigorous electromagnetic theory to analyze light propagation in tissue is almost impossible. Therefore, several approximate analysis approaches to model the light propagation in tissue were introduced. In this study we tried to measure the power of diffuse light on body surface non-invasively and brought the data into comparison. Five positions which the superficial tissues are different were selected and Automation Control Technology was used to improve measurement efficiency and accuracy. Our study suggests that the distributions of diffuse light along different paths on the surface of skin are conformed to exponential attenuation law but the attenuation coefficients are different. Otherwise, the exponential attenuation coefficient of the same position is also influenced by the gender of subject.

Heavy water gas (D2O gas) which owns special structure property, can generate terahertz radiation by optically pumping technology, and its 385 μm wavelength radiation can be widely used. In this research, on the base of semi-classical density matrix theory, we set up a three-level energy system as its theoretical model, a TEA-CO2 laser 9R (22) output line (λ = 9.26 μm) acted as pumping source, D2O gas molecules were operating medium, the expressions of pumping absorption coefficient G p and Terahertz signal gain coefficient G s were deduced. It was shown that the gain of Terahertz signal was related with the energy-level parameters of operating molecules and some operating parameters of the Terahertz laser cavity, mainly including cavity length. By means of iteration method, the output power density of Terahertz pulse signal was calculated numerically. Changing the parameter of cavity length and keeping others steady, the relationship curve between the output power intensity (Is) of Terahertz pulse laser and the operating cavity length (L) was obtained. The curve showed that the power intensity (Is) increased with cavity length (L) in a certain range, but decreased when the length (L) exceeded some value because of the absorption effect, and there was an optimal cavity length for the highest output power. We used a grating tuned TEA-CO2 laser as pumping power and a sample tube of variable length in 70–160 cm as terahertz laser operating cavity to experiment. The results of theoretical calculation and experiment matched with each other, and it is helpful for miniaturizing terahertz laser volume to make it practical.

The nanotubes were prepared by the dc arc-discharge method in helium and argon gas ambient under controlled pressure, and subsequently purified by oxidation in air. The room temperature electron spin resonance (ESR) spectra of purified carbon nanotubes prepared under different inert gases and their pressure were measured. The dependence of the ESR line shape, linewidth, g-value of the nanotubes on the inert gases and their pressures is found and discussed.

Reflection spectra of human Laogong acupoint (PC8) and non-acupoint tissue which irradiated by different power were studied in the spectral range from 400 nm to 1000 nm in vivo. A wavelength of 808 nm semiconductor laser was used for irradiation at the power of 0 mw (empty irradiation), 20 mw, 50 mw and 100 mw for ten minutes. Reflection spectra were measured with an AvaSpec-2048 optical fiber spectroscopy with an integrating sphere attachment. The result shows that when empty irradiated, the shape of the reflectance spectra of Laogong acupoint and non-acupoint are similar, they have the same troughs at 423 nm, 544 nm, 577 nm and 980 nm, the reflectance at these wavelengths for Laogong acupoint are 17.1%, 26.1%, 25.9%, 35.0%, and for non-acupoint are 17.1%, 27.6%, 28.1%, 36.5%. But from 475 nm to 1000 nm, the reflectance of Laogong acupoint is smaller than that of non-acoupoint. After irradiated by laser at the power of 20 mw, 50 mw, and 100 mw, there is a very significant decrease in the reflectance spectra of Laogong acupoint comparing to that of empty irradiated, and the higher power, the lower reflectance. But there is just a small decrease in the reflectance spectra of non-acupoint comparing to that of empty irradiated. From the above results, it is clearly to see that Laogong acupoint is more sensitive than non-acupoint when irradiated by semiconductor laser.

A new method to detect infrared single photon using avalanche photodiodes is proposed, which combine the requirements of a single photon detector control circuit and features of the electric pulses generator by transient process of transmission lines. When the terminated boundary conditions of transmission lines are changed quickly, voltage across the switch devices will drop suddenly in the electric pulses generator model and at the same time a signal that can reflect the drive information of the switch device will export from load resistance. So we can replace the switch with avalanche photodiodes who can act as an excellent optoelectronic switch. Then when faint laser pulses enter the avalanche photodiode, resistance of the avalanche photodiode will decrease quickly and with that voltage across avalanche photodiodes will drop simultaneously and a signal that can reflect the single-photon laser pulses will export from the load resistance. The simulation results are given for the new quenching circuit model of avalanche photodiodes and the analyses emphasis on the feasibility of the quenching model and the influence of each electrical component on the performance of the quenching circuit. Finally optimal parameter of the electrical components in the model is demonstrated.

We present implementation of phase modulated polarization coding by polarizing sagnac interferometers. At four different low input voltages of the phase modulator, coder encodes pulse into four different polarization states, 45°, 135° linearly polarized or right, left circle polarized, while the decoder serves as the complementary polarizers. The mean visibility of the system is tested at 94.31%.

This paper introduces the design of a single photon detector based on the AT89C51 single chip microcontroller for quantum key distribution at telecommunication wavelengths. An avalanche photodiode (APD) is operated in Geiger mode and stabilized at temperature of 228K for translating the single photon signals into electrical pulses. The photon induced avalanche pulses are amplified and converted to digital data. The microcontroller discriminates the data, counting the number of photons, and then displays the photon number and the detection efficiency on a LCD display. The instrument can effectively support the study of quantum key distribution.

The evolution properties of the self-similar parabolic pulse(similariton) with higher-order effects in microstructured fiber amplifier with normal group-velocity dispersion are investigated in this paper. The numerical results show that the higher-order effects greatly distort similariton's waveform, frequency and the linearity of chirp. The drift of pulse center increases with distance. The influence of different higher-order effects on similariton is analyzed. High quality propagation of similariton can be attained by manipulating the geometrical parameters of the microstructured fiber amplifier. These results are significant in the further study of similariton propagation in high-power ultrashort fiber amplifier, laser and transmission system.

To find out the mechanism of modulating the deformability of erythrocytes with low intensity He-Ne laser action, we studied the effect of low intensity He-Ne laser on the ultrastructure of human erythrocyte membrane. Erythrocytes were treated with free radicals from a Fenton reaction system before exposing them to low intensity He-Ne laser. The ultrastructure of damaged erythrocyte membrane was examined by atomic force microscopy. The results showed that the erythrocyte membrane became very rough and the molecules on the surface of the membrane congregated into particles of different magnitudes sizes after treating with free radicals. Comparing the degree of congregation of the molecular particles in the non-irradiated group and the He-Ne laser irradiated (9 mW and 18 mW) group, we found the average size of molecular particles in the laser irradiated group was smaller than that in the non-irradiated group, indicating that the low intensity laser had repairing function to the damage of erythrocyte membrane produced by the free radicals.

This paper aims to evaluate the curative effects of low-intensity laser external radiotherapy through thermal texture mapping (TTM) technology. The influences of 30 min nasal cavity irradiation of semiconductor laser (650 nm, 5 mW, continuous wave) on microcirculation were investigated through TTM. At the same time, with the aid of TTM, the influences of the irradiation on the whole body thermal balances and the functions of the liver and kidney were also studied. Altogether, 32 cases of microcirculation depression were investigated. After the 30 min nasal cavity irradiation, the total efficiency of microcirculation reached 100%. The effective ratio kept 96.9% 30 minutes later but the effect almost disappeared completely 150 minutes after the irradiation. No ill influence on the whole body thermal balance or metabolic functions of liver and kidney was found. Low-intensity laser external radiotherapy was a promising therapy to improve microcirculation. TTM was the ideal evaluation technology promoting this therapy.

It was commonly accepted that the effect of low intensity laser irradiation modulated the deformability of erythrocyte. But the idiographic mechanism is still unclear. The purpose of this study was to find out this mechanism through studying the effect of low intensity He-Ne laser on ultrastructure of healthy human erythrocyte membrane, which was treated with free radical of Fenton reaction system prior to exposure to low intensity He-Ne laser. We have analyzed the surface ultrastructure of damaged erythrocytes from a microscope viewpoint by atomic force microscope (AFM) featuring nano meterscale visualization. The results showed that the erythrocyte membrane became very rough after treated with free radical, the molecules on the surface of membrane congregated form different magnitude of particles. Comparing with the non-irradiated group (control group), the extend of congregation of the protein molecular particles by the power of 9 mW and 18 mW He-Ne laser irradiated group had been improved respectively. The average size of molecular particles changed smaller than control (control:66.41 nm, 9 mw: 62.50 nm, 18 mw: 54.69 nm), and the effect that the erythrocyte was irradiated by the power of 18 mw was better than the one irradiated by the power of 9 mw. To some extent, there was a repaired function for low intensity laser to the free radical damaged erythrocyte membrane. The mechanism of low intensity laser irradiation improved the deformability of free radical damaged erythrocyte possibly through laser irradiation recovered the normal molecular conformation on the erythrocyte membrane. AFM images provide a more direct-viewing method for studying the mechanism of low intensity laser irradiation improving the deformability of erythrocyte.

Low intensity monochromatic light or laser irradiation (LIL) has been widely used to diagnose biosystems, but the photobiomodulation (PBM) of LIL on the diagnostic biosystems was not always considered. PBM and its mechanism have been deeply studied. In this paper, PBM mechanism is used to study the PBM of diagnostic LIL (DPBM) so that the affection of DPBM can be really ignored.

Based on Pennes equation, the influences of the intensity and the impulse frequency of laser acupuncture on the point tissues' blood flow perfusion rate are discussed. We find that the blood perfusion rate of point tissue increases with the intensity of laser acupuncture increasing. After impulse laser acupuncture the point tissue blood perfusion rate increase little, but after continuum laser acupuncture the point tissues blood perfusion rate increase much.

Laser surgery provides good exposure with clear operating fields and satisfactory preliminary functional results. In contrast to conventional excision, it was found that matrix metalloproteinases and the tissue inhibitors of metalloproteinases -1 mRNA expression is higher, myofibroblasts appeared and disappeared slower in laser excision wounds. It has been suggested that the better anatomical and functional results achieved following laser cordectomy may be explained by the fact that such procedures result in better, more rapid healing processes to recover vocal cord for early glottic tumors and better. In this paper, the role of photobiomodulation in laser surgery will be discussed by the cultured monolayer normal human skin fibroblast model of the photobiomodulation of marginal irradiation of high intensity laser beam, the photobiomodulation related to the irradiated tissue, the biological information model of photobiomodulation and the animal models of laser surgery. Although high intensity laser beam is so intense that it destroys the irradiated cells or tissue, its marginal irradiation intensity is so low that there is photobiomodulation on non-damage cells to modulate the regeneration of partly damaged tissue so that the surgery of laser of different parameters results in different post-surgical recovery. It was concluded that photobiomodulation might play an important role in the long-term effects of laser surgery, which might be used to design laser surgery.

Quantum key can be theoretically demonstrated to be secure and now commercially available. The bit rate of the quantum key distribution is much lower than that for "one-time pad" needs. The practical bit limitation of the quantum key distribution system is analyzed to explain necessity for bit amplification. The method of bit amplification is also introduced in this paper.

Photobiomodulation is an effect of low intensity monochromatic light or laser irradiation on biological systems, which stimulates or inhibits biological functions but does not results in irreducible damage. However, many cellular experiments, animal experiments or clinic studies with monochromatic light or laser irradiation which intensity is not so high that it directly destroys cells have found no photobiomodulation but cell compartment damage, apoptosis or necrosis so that a new concept, a moderate intensity laser or monochromatic light, should be defined if its intensity is so high that no photobiomodulation can be observed, but is so low that it can not directly destroy cells. There might be two pathways mediated the effects of a moderate intensity laser or monochromatic light: one is mediated by the photodynamic effects of endogenetic photosensitizers to induce apoptosis or necrosis, one is mediated by laser or monochromatic light induced stress wave through endogenetic chromophore to induce apoptosis. These effects can be used to understand laser or monochromatic light induced cell compartment damage, apoptosis or necrosis. They are beneficial in phototherapy of cancer and scar, but deleterious in phototherapy of delayed onset of muscular soreness.

Light-emitting diode (LED), smaller and less expensive, requires less power than laser does, is more and more popular in studying photobiomodulation. Three new LED systems with different intensity have been designed in this paper. The three LED systems consist of a set of lens to expand the beam of light or/and to focus the rays of light, and an array of LEDs set in the sphere connected with Fresnel lens. The intensity of the three LED systems ranges from: 0.002 to 1.465 W/m 2 with the spot diameter 40 mm; 0.358 to 11.229 W/m 2 with the spot diameter 60 mm; 17.626 to 115.371 W/m 2 with the spot diameter 80 mm. Their experimental formulae for calculating intensity were obtained by SPSS.

The Light-emitting diodes based on III-nitride wide band gap semiconductors, which have a photonic crystal slab consisting of a graphite lattice of pillars on the cladding layer, is constructed. The vertical z direction optical output energy of the Light-emitting diodes is calculated by three-dimensional finite-difference time-domain method. The results show that the two-dimensional graphite-arranged pillars with a thick pillar in the middle can be utilized to enhance the light extraction. The tower-like pillars, which are thin on the top of the pillars and thick in the root of the pillars, benefit the light extraction when the angle of the tower-like pillars is proper. The optical output energy varies randomly with the change of PC columns in size and site in some extents randomly, but does not change very much.

Temperature is a long established indicator of health. With the advancement of clinical medicine in thermal disease diagnostics, understanding the thermal life phenomena and temperature behavior has become increasingly important. The biological effects of human exposure to low-intensity laser irradiation thermo-therapy, the best established are those due to elevation of tissue temperature. Bio-heat equations (BHEs) are necessary for predicting tissue temperature during thermal treatment. To prevent harmful levels of heating, restrictions have been proposed on low-intensity laser irradiation as the external spatial heating. In this paper, considering the different properties for the pathological tissue and the normal tissue, using a numerical method to solve the Pennes’ bio-heat equation, we analyzed theoretically the relationship between the temperature distribution and external spatial heating during low-intensity laser irradiation. The effects of the thermal parameters such as the heat conductivity, blood perfusion rate, and metabolic rate of the tissues on the temperature distribution were discussed. The results can be used to predicted different effects on the temperature variation and distribution, the thermal damage distribution and the thermal damage volume etc. The results are also useful in optimizing the therapeutic parameters for improved low-intensity laser irradiation treatments and for better understanding the thermal life phenomena in living tissues.

InP self-assembled structure were grown by MOCVD method on GaInP epitaxial layer mismatched to the GaAs substrate and were measured by employing the Near-field Scanning Optical Microscopy (NSOM) and SEM. The distribution of self-assembled islands was analyzed from the NSOM images and SEM results based on the scaling theories. It is found the distribution periodicity of the islands along [110] direction is improved and 1μm separation is obtained. The regular distribution was found along [1-10] direction. It shows and the mismatched epitaxial layer could improve the distribution periodicity of the islands along [110] and [1-10] direction. The experiment gives a potential way to realize the ordered two-dimensional distribution of the self-assembled structure. A mode, based on the shear force boundary and QD sphere, was established to explain the difference of our results between the topography and NPC. The size of islands could be evaluated by NSOM if the diameter of the probe has been taken account on.

Liu TCY et al have suggested the membrane receptor mediated signal transduction mechanism (STM) on photobiomodulation, which was verified by successful applications. In this paper, STM is extended to virus, and called electron excitation. As the frequency of the absorption light of envelope glycoproteins is greater than the one of light from UVA (320-400 nm) to IR, the envelope glycoprotein absorption of the light is non-resonant, and its transition rate is extraordinarily small, but can be amplified by the coherent state of the identical and independent envelope glcyoproteins. We apply VSTM to discuss the possibility that light from UVA to IR is used to inactivate the coronavirus of severe acute respiratory syndrome.

Light-emitting diode (LED) technology has provided medicine with a new tool capable of delivering light deep into tissues of the body, at wavelengths which are biologically optimal for cancer treatment, wound healing and other clinical applications. In this paper, a simple review on the clinical use in therapeutic applications as well as in laboratory work of LEDs is given in view of low intensity laser irradiation effects in biomedicine.

Laser acupuncture as an alternative, noninvasive, painless and cost-effective therapy is widely used for acute and chronic pain, nausea, circulatory functions, and mood-related behavioral disorders. It was suggested one of the pathways mediated laser acupuncture was from laser biomodulation on acupuncture point cells to autonomic nervous subsystems through meridian. As laser irradiation used for acupuncture is red or infra red, we put forward the following model: at dose 1(100-3 J/m2), the irradiation activates parasympathetic nervous subsystem (PSN); at dose 2(103-5 J/m2), the irradiation activates sympathetic nervous subsystem (SN); at dose 3(105-6 J/m2), the irradiation activates PSN; and at dose 4(106-7 J/m2), the irradiation activates SN. This model was verified by its successful applications.

Background and Objectives Whether light emitting diode (LED) irradiation has effects on “β-amyloid (Aβ) induced apoptosis,” a leading hypothesis of the cause of Alzheimer's disease (AD), or not? Study Design/Materials and Methods Monolayer cell cultures of PC12 were subjected to Aβ or/and LED irradiation at various intensity. Cell apoptosis was confirmed by morphological criteria, DNA fragmentation assay, and FAScan flow cytometer assay. Results Treatment of the cells with LED irradiation significantly diminished Aβ induced apoptosis within 24 hours. Conclusions The LED irradiation, when utilized at power of 0.9 W/m2 and 60 minutes has significantly diminished Aβ induced apoptosis of PC12 cells. Lasers Surg. Med. 33:199–203, 2003. © 2003 Wiley-Liss, Inc.

Only one Mach-Zehnder interferometer is used in the proposed quantum bit distribution system where the two arms composing the Mach-Zehnder interferometer have been used as the transmission line. The loss of the photons due to absorption will decrease and the wavelets composing the photon are expected to transmit longer distance. The optical cable which contains many fiber belts which contain many fibers in parallel that is possible to make a Mach-Zehnder interferometer with its two arms as long as possible. This transmission system uses only two couplers and physically ensures transmission security.

Photon traditional Chinese medicine (PTCM), and inter- discipline of photonics and traditional Chinese medicine (TCM), studies TCM, such as the diagnostics, therapeutics, indistinct disease theory, rehabilitation, health care and so forth, by using photonics. IN this paper, we will give an introduction of PTCM and review its progress in the collective interaction of low intensity laser irradiation with biological systems, the propagation of low intensity laser irradiation through tissue, the biophotonics representation of acupoint, low intensity laser therapy, TCM laser hemotherapy, laser acupuncture. In this paper, the concept of biological unit was put forward for acupoint and cell membrane receptors to be considered as an identical particle model. The interaction of identical particles was studied by quantum chemistry, as well as the response of the system interacting with physical factors by the time quantum theory on radiation-matter interaction. It was shown that the identical particles from coherent states, the response rate of the super-change state is a linear function of N2 and N3 (N is the particle number), and the one of the sub-change state is zero. Its application led to the explanation of the contribution of biological unit number of acupoint to acupoint specificity and the contribution of cell membrane receptors to low in tensity laser irradiation. The comparative research of acupoint effect and cell function with biophoton emission showed that acupoint states and the membrane receptor state are related to body diseases.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Gaussian distributed index change, in which its d.c. component keeps constant, is achieved by using the double exposure technique with a uniform phase mask and Gaussian UV laser beam. The reflected spectral sidelobes of the grating can be suppressed to below -30 dB and the related channel bandwidth is as narrow as expected.

In this paper, the roles that the light of PDT plays were classified into two kinds, PDT and PDT2. PDT1 is mediated by photosensitizer. PDT2 results from the direct interaction of light with target cells. As only the photosensitizers in the membrane of a cell can be in the coherent state, PDT is mediated by the coherent interaction of membrane photosensitizers, and its main target is the membranes of a cell. PDT2 is governed by the biological information model of low intensity laser (BIML) put forward by Liu TCY et al (SPIE 3863-91). According to BIML under the dose of PDT, cold-color (green, blue or violet) laser irradiation activates adenylate cyclase through G s protein: cAMP↑; hot color (red, orange or yellow) laser irradiation activates cAMP phosphodiesterase through G i protein or activates phosphoinositide phospholipase C (PLC) through G q protein or activates one of receptor-linked enzyme: cAMP ↓. After reviewing simply the PDT effects on cells from the viewpoint of information biology and the research on them by use of optical spectroscopic approach, we arrived at the conclusion that cold color light PDT is better than hot color light PDT from the viewpoint of the effects on cell and the short term effects on cancer, but hot color light PDT is superior to cold color light PDT with respect to the long term effects on cancer.

This paper describes the theory, structure and technology of the laser carving machine. The method of two-rods bonding double-pumped in the same cavity used is used to get high power laser. The deflection of the oscillation is controlled by computer software. Basing on the property of the carved materials, we must use the software to adjust the laser pulse width and repeated frequency. The nonlinear effect can be rectified by software. On the two carving methods, the scanning method is suitable for carving image, while the method of vector graph is suitable for carving graph, because the oscillation has the property of speedy positioning.

GD 510631, ChinaABSTRACTLiu TCY et al. (Chinese Journal of Laser Medicine & Surgery. 6(3), pp. 125-131, 1997) have put forward the biologicalinformation model on low intensity laser irradiation (BIML) and the biological information model (BITML). According toBIML, low intensity laser irradiation couples with intracellular messenger through the chromophore absorption in the cellmembrane: hot-color (red, orange, yellow) laser irradiation activates cAMP phosphodiesterase through G, protein, oractivates phosphoinositide phospholipase C (PLC) through Gq protein, or activates one of receptor—associated kinases: cAMPL; cold-color (green, blue, violet) laser intadiation activates adenylate eyelase through G. protein: cAMP'l'. Accordingto BITML, if the laser irradiation dose is greater than the corresponding threshold vale, its function would be the function ofits complementary color. In this paper, After laser effects were classified into two kinds: direct effects and indirect effects,BIML and BITML were applied to studying the mechanism of intravascular He-Ne laser irradiation on blood and its clinicapplications.Key words: intravascular low intensity He-Ne laser irradiation on blood; mechanism; clinic1. INTRODUCTIONThe therapy of the intravascular low intensity He-Ne laser irradiation on blood (ILIB) has been developed in 1980s inUSSR. The systematic research on ILIB and its clinic applications has not been done until 1990s in China[l]. Animalstudies and human trials on whole blood have shown that TUB can change hemorheological parameters, adjust body's

In this paper, we put forward the quasi-hormone model on laser biostimulation (QHML) and the quasi-peptide-hormone model on laser biostimulation (QPHML). QHML supposes the chromophore absorption in a cell allows the photon of low- energy laser irradiation to act as a carrier of bio- information as a hormone does. QPHML further supposes the chromophore absorption in the cell membrane couples with intracellular messenger through GTP-binding protein and mediates laser biostimulation as following: Hot color laser irradiation activates cAMP phosphodiesterase through Gi protein or activates phosphoinositide phospholipase C through Gq protein: cAMP$ARDN, cGMP $ARUP. COld-color laser irradiation activates adenylate cyclase through Gs protein; cAMP$ARUP, cGMP$ARDN. QPHML is verified by its successful applications at the cellular level, the clinic level, and the epidemiological level. In this paper, we also study light-cell interaction from time viewpoint. We define a time representing a process, and show the time parallel principle representing the time relationship of two weakly coupled processes. We then apply the time parallel principle to studying light-cell interaction mediated by the chromophore in the membrane, respectively, and provide theoretical foundation for QPHML.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this paper, we did integrated research of laser medicine and photonics from the viewpoint of system-specific time. After establishing system-specific time dependent Maxwell equations in vacuum and in medium, we derived the non-decay optical transmission condition. We then put forward the concept of biological units that interact with laser radiation directly, and discussed the coherent interaction of laser radiation with biological units in terms of identical particle model and system-specific time quantum theory. We also introduced time to represent processes, discuss the time-coupling relation of the interaction of laser radiation with biological units and the corresponding biological processes, and generated the biological information of photons of laser radiation.

A low-cost, large area, random, maskless texturing scheme independent of crystal orientation is expected to have an impact on terrestrial photovoltaic technology significantly. We investigated microstructured silicon formed by irradiating the surface of a Si wafer with femtosecond laser pulses in the presence of a sulfur-bearing gas. It is widely believed that microstructured silicon is a potential material for efficient multi intermediate bands silicon solar cell. Using a four-band model, the loss of sunlight for silicon with two different chalcogenide impurity bands was analyzed, and the levels of the minimum loss of sunlight can be found. Then the effect of the position at which the intermediate bands that have minimum sunlight loss rate on the theoretical conversion efficiency of the corresponding solar cell was discussed with the Detailed Balance Theory. After that, the influence of impact ionization on the efficiency of four-band Solar Cells was analyzed in detail. Finally, problems that need to be resolved in making intermediate band solar cell based on femtosecond laser microstructured silicon are pointed out with great emphasis.

Multiple diffraction rings are observed after a pulse laser beam passesthrough an absorbing dye LB film. The theoretical analysis, based on the model of transverse self—phase modulation, is also given. The saturated nonlinear refractive index n2 is estimated to be 2.0X10cm2/W from thenumber of rings induced In the LB films. The main contribution to this largernonlinearity is believed to be from laser-induced transformation between H— aggregates and monomers of molecules in the LB films.1. INTRODUCTION There are great needs for nonlinear optical (NLO) materials that can beused with low-intensity light sources for applications such as optical phaseconjugation, optical storage and switching, and laser power limiting. Langmuir-blodgett (LB) films have attracted much attention recently becauseof their larger nonlinearitlea enhanced by super- ordered packing of NLO active organic molecules [1]. So far, intensive investigations have been concerned with second harmonic generation[21, linear electro-optical effect 131

A novel light-emitting diode (LED) packaging method, named the active packaging (AP) method, is presented in this paper. In this method, during the LED packaging process, the light emitted from a GaN LED chip itself is employed to package the LED encapsulant, thereby eliminating the need to utilize a mold. Current injection into a bare LED chip, triggers a photosensitive epoxy to polymerize, leading to the formation of mushroom lamp cap on the LED chip. The emission properties of LEDs fabricated by this method, including their emission beam profiles and light outputs, were characterized. The results showed that a self-focusing effect happened with the addition of an epoxy on the chip. The simulation demonstrated that the geometry the encapsulant controlled the beam pattern of emission. Further, the self-focusing effect was believed to be caused by the combination of the threshold energy of epoxy polymerization, the beam pattern and the power output of the LED chip.