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We demonstrate a 355 nm ultraviolet nanosecond laser produced by the type I phase-matched frequency doubling in a K3B6O10Br (KBOB) nonlinear optical crystal. The use of 5022 μJ, 710 nm pump pulses at 10 Hz repetition rate produces 4.273 ns, 355 nm, 717 μJ pulses that corresponds to a frequency doubling conversion efficiency of 14.3%. The energy instability of the frequency-doubled pulse train measured is less than ±1% for maximum output pulse energy (∼717 μJ). Our experimental results show that KBOB is a promising nonlinear optical crystal for generating ultraviolet nanosecond laser pulses through frequency doubling.

We experimentally demonstrate an optical phase conjugation (OPC) enhanced transmission system based on the Kramers–Kronig direct detection scheme. The single-sideband signal is modulated at 80-Gb/s 16-QAM with orthogonal frequency-division multiplexing. In the 180-km transmission experiment, the OPC surpasses digital chromatic dispersion compensation in Q factor, optimum launched optical power (LOP) and optical signal-to-noise ratio (OSNR) sensitivity. The improvement in Q factor, optimum LOP and OSNR sensitivity are 0.9 dB, 1.0 dB, and 1.7 dB respectively. The superiority of OPC over pure optical dispersion compensation is also analyzed by simulation. The results indicate that the OPC is an effective means to enhance the transmission performance of single-sideband signals.

In this paper, we report the first demonstration of using silicon photonic integrated circuits for 62 Gb/s 4-quadrature-amplitude-modulation (4-QAM) orthogonal frequency-division multiplexing (OFDM) and 112 Gb/s 16-QAM OFDM over an 80-km standard single-mode fiber (SSMF) transmission with the Kramers–Kronig (KK) direct detection. Single sideband optical signals are generated by two silicon micro-ring modulators, and directly detected by a single integrated germanium-on-silicon waveguide photodiode fabricated in a multi-project wafer run. The complex optical field can be fully re-constructed by KK detection after an 80-km SSMF transmission. The integrated transceivers with KK detection are suitable for future low-cost, low-power, and small-footprint data center interconnects in the short and medium reach.

We experimentally demonstrate performance improvement of 5×10-Gbaud 16-QAM single-sideband signals using a carrier recovery block enabled by self-seeded Brillouin amplification after 80-km fiber transmission. The optimum average Q factor improvement is 3.0 dB.

Probabilistically shaped signals with intermediate constellation sizes are found to be relatively tolerant to laser phase noise. We demonstrate experimentally that PS-100 QAM is superior to PS-256 QAM for 200-kHz sum linewidth heterodyne detection.

A novel photonic analog-to-digital conversion (ADC) scheme based on time-to-frequency mapping is proposed and experimentally demonstrated. In the approach, the amplitude of the input analog signal is firstly converted into a time-varying signal by pulse position modulation, then the time variation is mapped into the optical spectrum with the help of time-to-frequency mapping offered by the chirped optical pulse. The optical spectral information can be directly encoded by using interleaving filters and a binary receiver array, which outputs the digital records of the input analog signal. Compared with the existing photonic ADC schemes, the proposed approach greatly simplifies the system configuration and uses only one modulator with a dispersive element to achieve 2 N quantization levels. Meanwhile, it also avoids the limitation of optical nonlinearity and realizes the linear mapping between the analog voltage and optical spectrum. A proof-of-concept experiment of the proposed approach based on time-to-frequency mapping is successfully carried out to verify the feasibility of the scheme. In addition, we also discuss the performance limitations induced by the frequency ambiguity in chirped spectra and the timing jitter in sampling.

The signal-signal beat noise mitigation performances of the original received signal, the square root processed signal, and the Kramers-Kronig processed signal are experimentally compared in a 110 Gbit/s probabilistically-shaped 64 QAM direct detection system.

Hypothalamic-pituitary-ovary (HPO) axis is a dominant system controlling ovulation during puberty. Electro-acupuncture (EA) has been widely used to cure the reproductive diseases associated with endocrinological disorders. However, whether EA treatment affects HPO axis activity of physiological animals and induces alterations on the hormones in the HPO axis was also unclear. Here, we performed the EA stimuli on bilateral acupoints of Sanyinjiao (SP6) and Zusanli (ST36) on female virgin rats every 3 days and for a total of 5 times. The results showed that GnRH levels in hypothalamus were greatly upregulated in EA-treated rats than untreated animals at day 7 and 13. The serum levels for FSH and LH were severely reduced after EA treatment compared with EA-untreated animals at day 1, while they were greatly increased at day 7 and 13. The serum concentrations of 17β-estradiol were lower in EA-treated rats versus untreated animals at day 7, while they were higher in EA-treated rats than other groups at day 13. However, the progesterone concentrations were lower in EA-treated rats than Control and Sham-EA rats both at day 7 and 13. More importantly, we found that the prostaglandin E2 level in serum was reduced in EA-treated rats versus untreated rats at day 1, while they were upregulated at day 7 and 13. Conversely, the norepinephrine level in serum was increased at day 1, while they were decreased greatly in EA-treated rats versus untreated rats at day 7 and 13. The current results demonstrated that EA could modulate homeostasis of HPO axis in physiologic rats, which would be useful to clarify the mechanisms of EA application on pathological and physiological animals or human.

We propose to utilize the Hermitian symmetry of carrier-less amplitude phase (CAP) signals to mitigate distortion caused by fiber nonlinearity. The upper and lower frequency sidebands of CAP signals constitute phase-conjugated twin waves. Hence, coherent superposition of the two sidebands at the receiver can improve signal-to-noise ratio and compensate nonlinear impairment. We experimentally demonstrate that this scheme can improve the $Q$ factor by ~1.6 dB after 80-km transmission. When the fiber length is extended to 240 km, the $Q$ factor still exceeds the 7% hard decision forward error correction threshold by ~0.4 dB, showing potential application of the scheme for access and metro networks.

We demonstrate carrier-to-signal power ratio (CSPR) enhancement by self-seeded stimulated Brillouin scattering to improve the performance of Kramers–Kronig (KK) detection for multichannel single-sideband (SSB) signals. By virtue of low-CSPR transmission and high-CSPR detection, our proposed scheme effectively advances system performance by reducing propagation-induced distortion while maintaining the minimum phase condition. We experimentally demonstrate the improvement in CSPR and bit error rate of 5 × 10 -Gbaud 16-QAM SSB signals by applying the carrier recovery block after 80-km transmission. Under optimum pump power, the average Q factor improvement of all five channels is 3.0 dB. We also analyze the performances of different channels and the major limiting factor. The results verify that our scheme offers a promising solution to enhance SSB self-coherent KK detection in wavelength-division multiplexing systems.

We demonstrate performance enhancement of a Kramers-Kronig direct-detection system by utilizing mid-span optical phase conjugation. The optimum Q factor is improved by 1.8 dB. The optimum carrier-to-signal power ratios at different launched powers are analyzed.

Stimulated Brillouin scattering has been adopted to regenerate an optical carrier from a single sideband signal. The carrier is applied for locking two frequency combs at the transmitter and receiver in a multi-wavelength communication system. Kramers-Kronig detection of 5 × 10 Gbaud QPSK/16-QAM channels is successfully demonstrated.

We propose a compact and high-speed I/Q modulator based on two germanium-on-silicon Franz-Keldysh electro-absorption modulators. We demonstrate a 4-QAM signal transmission and reconstruct the complex signal in a Kramers-Kronig receiver for future datacenter interconnect applications.

We proposed a novel scheme for realizing Kramers–Kronig detection by utilizing the narrow-band and high-gain characteristic of stimulated Brillouin scattering. At the receiver, the weak virtual carrier located at the edge of the signal spectrum is Brillouin amplified by the output of a slave laser, which is injection locked by a weak pump seed provided by the transmitter. More than a 2.7-dB optical signal-to-noise ratio sensitivity improvement is experimentally obtained compared with the traditional virtual carrier assisted scheme after an 80-km transmission. The effective number of bits requirement and the performance gain in the nonlinear transmission are both analyzed by the simulation.

We experimentally demonstrate Kramers-Kronig detection of an independent sideband (ISB) signal by Brillouin amplifying a weak pilot tone at the receiver side. A 30Gbit/s ISB signal with mixed modulation formats is successfully transmitted over 80 km.

We demonstrate that polarization multiplexing signals can be detected by a single-ended photodiode after beating with a pair of orthogonal and staggered carriers. The feasibility of proposed scheme is verified by 8Gbaud PDM-QPSK signals.

We show that the upper and lower sidebands of a multiband carrier-less amplitude phase (CAP) signal fulfil the condition of phase-conjugated twin waves. Through simulation and experiments, the reduction of intrachannel and interchannel nonlinear distortions are demonstrated. The optimum launched power for 200 km transmission is improved by 2 dB in a two-channel wavelength division multiplexing (WDM) system.

We present experimental investigation on detection approaching 0.55 photon per pulse at 1064 nm using a 1 kHz 355-nm pumped picosecond optical parametric amplifier (OPA) with uncooled ordinary Si-CCD. The gain factor of the OPA is measured to be ~5.75×107. The ultra-weak signal detection is achieved by significant improvement of the signal-to-noise ratio (SNR) of the OPA, which is realized by suppressing the superfluorescence background utilizing long distance detection and spatial filtering in the light path, and reducing the fluctuation of total output of the OPA with large sampling number of laser shots.

We investigate the optimal constellation size for probabilistic shaping (PS) under the constraint of different effective numbers of bits (ENOB) of the analog-to-digital converter (ADC) at the receiver. For a fixed entropy, increasing the constellation size brings a larger shaping gain, while it also leads to a higher peak-to-average-power ratio, which makes the signal more sensitive to the ENOB and fiber nonlinearity. Our experimental results show that PS-44 quadrature amplitude modulation (QAM) outperforms both PS-64 QAM and uniformly shaped 32 QAM (U-32 QAM) when the ENOB of ADC is lower than 4.5. The optimal launched power and the maximum achievable distance for U-32 QAM, PS-44 QAM, and PS-64 QAM are analyzed by simulation.

Rationale: As increasing frequency of serotonergic drug use, SS (serotonin syndrome) occurred more than ever. But clinicians have not enough knowledge and experience about SS as a potentially life-threatening condition. SS is usually caused by the increased serotonin activity in the central nervous system which may due to a serotonergic agent overdose or the concomitant use of 2 or more serotonergic antidepressants. We report a case of SS due to a normal dose of selective serotonin inhibitors (SSRIs) thus to remind clinicians to pay attention to such patients and make an early diagnosis and initiation of therapy in the clinical practice. Patient concerns: We report here a 49-year-old man presented with lethargic, less communicative, and insomnia for 20 days while a diagnosis of depression was considered and he was treated with SSRIs. Diagnosis: The patient in our case fulfilled the 3 criteria existed now for diagnosing SS, including the Sternbach criteria, Radomski revised diagnostic criteria, and the Hunter serotonin toxicity criteria. Interventions: All the antidepressants were stopped and cyproheptadine with an initial dose of 12 mg a day was started along with supportive care. The patient was also admitted to emergency intensive care unit for further treatment. He was sedated and paralyzed by intravenous Midazolam and Clonazepam along with physical cooling and supportive care. Outcomes: All of the patient's symptoms abated gradually and he soon could get off the bed and be communicative. Finally, the patient made a full recovery and he was discharged from the hospital. Lessons: Our case suggests an atypical clinical course while the medicine the patient takes was not in so much dose. We assumed that there may have been some variation in metabolism of these agents, resulting in increased possibility that led to the subsequent syndrome. Thus, it is essential for clinicians to keep in mind when patients taking serotonergic agents who demonstrate acute change in their mental status. Besides, clinicians should be aware of such patients who seem to be sensitive to SSRIs, who may require a genetic testing before the initiation of SSRI therapy.

Objective To explore the relationship between sagittal plane and coronal plane curvatures in guppies by investigating the curvature angles of sagittal and sagittal-coronal guppies. Methods After mating between 1000 spinal curvature guppies, 124 guppies (3-month old) were screened from progenies for the present study. Photos of all fishes were taken and the sagittal and coronal angles were calculated via angle measure tool of Photoshop 12.0 software. All data were analyzed by SPSS 11.0. Results In sagittal and sagittal-coronal curvature guppies, there was a significant linear correlation between sagittal angles and coronal angles. In 48 sagittal-coronal curvatures, their sagittal angles were above 40°, meanwhile, in 76 sagittal guppies, their sagittal angles were mostly below 40°. Conclusions These findings indicated that the occurrence of coronal curvature might be later than sagittal curvature and could be influenced by other factors. Sagittal angles 40° might be involved in the onset of coronal curvature.

We present the experimental results on pushing the detection of ultra-weak signal using a 355 nm pumped picosecond collinear optical parametric amplifier (OPA). The signal is the second harmonic pulse of a passively/actively mode-locked Nd:YAG laser at 532 nm. The measured gain factor of this amplifier is found to be similar to 1.36 x 10(8), and the detection limit is similar to 1.03 aJ per pulse, corresponding to 3 photons at 532 nm within the 15 ps time window of the pump pulse. This was achieved by increasing the distance between the CCD detector and the OPA. It led to a significant reduction of parametric superfluorescence background so that the amplified spot can be observed under the detection limit condition. Compared with previous reports, the detection limit is improved by one order of magnitude. (C) 2012 Elsevier B.V. All rights reserved.

This paper presents a continuous wave and a Q-switched Nd:YAG laser pumped by diode laser at 885 nm. The maximum output power of the CW laser is 8.28 W with an absorbed slope efficiency of 35.01%. The Q-switching is achieved using a V3+:YAG crystal as the saturable absorber. The maximum output power of the passively Q-switched laser is 3.55 W with an absorbed pumping power of 28.65 W operated with a dual wavelength at 1319 and 1338 nm. The shortest pulse widths of the Q-switched laser are 20.20 and 20.86 ns, with a maximum repetition rate of 64.10 kHz.

A self-Q-switched Cr, Nd:YAG laser operating at 1064 nm under direct pumping at 885 nm is demonstrated. The 885 nm direct pumping scheme shows some advantages over the traditional pumping scheme at 808 nm. The slope efficiency increases by 10%, and the threshold decreases by 3.5%.

Background Transverse patella fractures are the most common type of patella fractures. Minimally invasive surgical technique for treatment of transverse patella fractures with the Cable Pin System has not been previously reported. Methods Thirty-four patients with displaced transverse fractures of the patella were included in this prospective study and were operatively treated by the Cable Pin System with a minimally invasive technique. Postoperative evaluation was based on radiographs, Visual Analog Scale of pain, range of motion, and Bostman grading scale. Results A total of 31 patients were finally included, with an average follow-up period of 21 months. The average operation time was 48 minutes. Intraoperative fluoroscopy was used for 2 to 4 times (average: 2.4 times). Radiographic evidence of solid fracture union was observed in all cases in a mean period of 7.2 weeks. The Visual Analog Scale score for pain was 3.3 ± 1.4 and 1.5 ± 1.3 at 4 weeks after surgery and when radiographic fracture healing was achieved, respectively. Twenty-nine patients achieved full knee range of motion, while two patients had 10° loss of full flexion at the final follow-up visit. The average Bostman score was 29.1/30 (range, 27-30) at 1 year after surgery, and an evaluation of "excellent" was observed in 30 patients at the final follow-up visit. Conclusion Surgical treatment of transverse patella fractures by the Cable Pin System with a minimally invasive technique was shown to provide satisfactory clinical results and excellent knee functions, with less pain and low incidence of complications. It could be a new option for treatment of transverse patella fractures.

Between March 2003 and September 2007, 170 consecutive patients with lumbar degenerative disease were studied retrospectively. Eighty patients underwent posterior lumbar interbody fusion (PLIF group) with pedicle screw (PS) fixation, and 82 patients underwent posterolateral fusion (PLF group) with PS fixation. Eight patients were lost to follow-up. The minimum follow-up period in each group was 2.0years. The mean follow-up period for the PLIF group was 3.6years, and for the PLF group, the mean follow-up was 3.4years: there was no significant difference between the two groups for length of follow-up. The Pain Index (PI) improved from 66 to 27 in the PLF group (p0.001) and from 69 to 29 in the PLIF group (p0.001), but there was no significant difference between the two groups (p0.05). In the PLF group, the preoperative mean Oswestry Disability Index (ODI) score was 34.5, which reduced to 14.2 at the final follow-up. In the PLIF group, the mean preoperative ODI was 36.4, which reduced to 16.2 at the final follow-up. There was no significant statistical difference between the two groups for ODI (p0.05). Eighty-eight percent (n=72) of patients in the PLF group and 91% (n=73) in the PLIF group had radiologically confirmed union, with no significant difference in fusion percentage between the two groups (p0.05). Twenty-two of 162 patients (14%) underwent a second operation: 18 (22%) in the PLF group and four (5%) patients in the PLIF group (p0.001). The clinical and functional outcomes in both groups were similar, and no significant difference was found in the parameters tested. Both surgical procedures were effective, but patients in the PLF group showed more complications related to hardware biomechanics than patients in the PLIF group (p0.001).

Background Fractures of the talar neck are relatively uncommon. The reported rates of avascular necrosis in Hawkins type II fractures vary from 34% to 50%. Various strategies have been adapted to prevent the occurrence of avascular necrosis. Methods We retrospectively reviewed the records of nine patients with Hawkins type II fractures. Open reduction and internal fixation with percutaneous cannulated screws were performed, and external fixation was used to unload the talus. A vascularized cuboid pedicle bone graft based on the lateral tarsal artery is adapted to improve the blood supply to the talar body. Postoperative radiographs were used to evaluate the adequacy of the reduction and the process of fracture healing. Osteonecrosis was defined on plain radiographs as any area of increased density of the talar dome relative to the adjacent structures. The postoperative global foot function was assessed using the Maryland Foot Rating Score. Results The average length of follow-up was 39 months (range, 16-58 months). The mean time to fixation was 54.4 hours. In all of the cases, the wound was closed primarily, and there were no postoperative infections or skin necrosis. Fractures healed uneventfully in all the patients with an average time to union as 15.6 weeks (range, 13-18 weeks). The avascular necrosis rate of talus was 0%. Hawkins sign was seen in one patient at 8 weeks after surgery in the anteroposterior view. According to the Maryland Foot Rating Score, excellent result (90-100) in seven cases and good result (75-89) in two cases were seen. Conclusion The use of a vascularized cuboid pedicle bone graft and combined internal and external fixation can effectively prevent avascular necrosis of the talus in preliminary study. Further randomized control research is necessary to clarify the effectiveness of this technique.

We propose an integrated vector modulator based on two compact and high-speed germanium-on-silicon Franz-Keldysh electro-absorption modulators. The proposed vector modulator is extremely compact with a total footprint of only 1800 μm×200 μm. We further experimentally demonstrate a 4-quadrature-amplitude-modulation (4-QAM) at 40 Gb/s over a 20-km standard single-mode fiber transmission. The complex signal is successfully re-constructed with a single-ended photodiode in a recently proposed Kramers-Kronig receiver for future low-cost, low-power, and low-footprint datacenter interconnect applications. The preliminary performance of the vector modulator with a 16-QAM is also investigated.

We demonstrate that an optical carrier can be extracted from a signal based on a blockwise phase-switching (BPS) technique for locking the frequency combs at the transmitter and the receiver in a wavelength division multiplexing (WDM) system. Two types of carrier regeneration techniques, optical injection locking and stimulated Brillouin scattering, are evaluated in the aspects of the injection ratio and pump power, respectively, under different carrier-to-signal power ratios. 7×16 Gbaud QPSK data channels with 25 GHz spacing are successfully transmitted over an 80 km fiber by the direct detection of a BPS-assisted central channel and coherent detection of the remaining channels.

We demonstrated a 1.21-W 532-nm picoseconds (ps) green laser via second-harmonic generation (SHG) using type-I phase-matched K3B6O10Cl (KBOC) as a nonlinear optical crystal. The ps green laser was successfully generated from two types of 1064-nm ps lasers with one being operated at 10 kHz and the other at 10 Hz. Using a 7.38-W pumping power at 10 kHz as the pump, the SHG output power at 532 nm was 1.21 W with a pulse width of 34.4 ps. For the 10-Hz ps laser with pumping energy of 4.95 mJ per pulse, the output at 532 nm was 1.78 mJ per pulse, which corresponds to an optical conversion efficiency of 36.0%. The experimental results show that the KBOC crystal is a promising nonlinear optical crystal for generating ps green laser.

The characters of stimulated Raman scattering of BaWO4 crystal excited by a picoseconds laser at 1064 nm are studied based on optical parametric amplification (OPA). Up to six-order Stokes components and five-order anti-Stokes components are observed. The SRS components are amplified by an OPA and the wavelength tunable range from 411 to 2594 nm is achieved with a maximum conversion efficiency of 38% using the OPA stage.

This publisher's note corrects an error in the title in Opt. Lett.43, 1367 (2018)OPLEDP0146-959210.1364/OL.43.001367.

The influence of annealing treatments and gamma-ray irradiation on the absorption and fluorescence spectra of Cr:GSGG crystals grown by the Czochralski method has been investigated. Two absorption bands located near 686 nm and 1050 nm were weakened markedly after the crystal was re-annealed in H2 atmosphere, which is due to the Cr4+ ions being de-oxidized into Cr3+ ions. The other two weak additional absorption bands induced by gamma-ray irradiation appearing near 310 nm and 480 nm are ascribed to the Fe2+ ions and F-type color centers, respectively. In particular, the gamma-ray irradiation with a dose of 100 Mrad has an effect of improving slightly the luminescence properties of Cr:GSGG crystals. The improvement mechanism is analyzed and discussed.

Bloom syndrome (BS) is an autosomal recessive disorder characterized by genomic instability and the early development of many types of cancer. Missense mutations have been identified in the BLM gene (encoding a RecQ helicase) in affected individuals, but the molecular mechanism and the structural basis of the effects of these mutations remain to be elucidated. We analysed five disease-causing missense mutations that are localized in the BLM helicase core region: Q672R, I841T, C878R, G891E and C901Y. The disease-causing mutants had low ATPase and helicase activities but their ATP binding abilities were normal, except for Q672, whose ATP binding activity was lower than that of the intact BLM helicase. Mutants C878R, mapping near motif IV, and G891E and C901Y, mapping in motif IV, displayed severe DNA-binding defects. We used molecular modelling to analyse these mutations. Our work provides insights into the molecular basis of BLM pathology, and reveals structural elements implicated in coupling DNA binding to ATP hydrolysis and DNA unwinding. Our findings will help to explain the mechanism underlying BLM catalysis and interpreting new BLM causing mutations identified in the future.

We report for the first time a diode-pumped simultaneous Q-switched and mode-locked 946 nm Nd:YAG laser with a diffusion bonded composite laser rod and a co-doped Nd, Cr:YAG as saturable absorber. The influence of the different initial transmission (T0) of the saturable absorber on the Q-switched and mode-locked pulse was experimentally demonstrated. At an incident pump power of 16.5 W, the average output power of 600 mW with 42 kHz repetition rate and 570 ns pulse width of the Q-switched envelope was generated. Almost 100% modulation depth with 205 MHz repetition rate of the mode-locked pulse within the Q-switched envelope was achieved when the incident pump power was 15 W.

Antiphase dynamics has been observed experimentally for the laser modes operation in a laser-diode-pumped Q-switched microchip Yb:YAG laser with GaAs as a saturable absorber in the presence of spatial hole-burning. The Q-switched pulses sequences of two modes at different pump power have been obtained. The experimental results have shown that the pulses sequences displayed classic antiphase dynamics. (C) 2003 Elsevier B.V. All rights reserved.

We synthesized US nanorods through a conventional solvothermal method and studied their photoluminescence and electric transport properties before and after annealing. High-resolution transmission electron microscopy indicated that the surface layer of the annealed US nanorods was well crystallized, while that of the unannealed nanorods was amorphous. Energy-dispersive x-ray spectrography, x-ray photoelectron spectrography and thermogravimetric analysis were used to demonstrate that the amorphous layer at the surface of the as-prepared nanorods was pure CdS. The photoluminescence spectra showed that after annealing the intensity of the band-edge emission increased several times and the surface state emission at 548 nm disappeared. The unannealed US nanorods had approximately linear I-V characteristics and the conductance suddenly increased about 100 times upon visible light illumination by a halogen lamp. The annealed US nanorods exhibited nonlinear conductance with a turn-on voltage at about 2.2 V. These properties show that US nanorods have potential applications in nanophotoelectric or sensing devices.

We have designed a single thin planar diffractive optical element ( DOE) based on the principle of diffractive optics to simultaneously split and concentrate the incident light into several energy ranges for lateral multijunction solar cells. A prototype with the maximum thickness of 6.95 mu m and 32 quantized levels in depth was fabricated by photolithographic technology. The spectrum-splitting and concentrating performance of the prototype, which were measured quantitatively, show good agreement with the simulation results. As mass production of a DOE can be produced by imprint technology, our design provides a feasible means for low-cost, large-scale, and high-efficiency photovoltaic applications. (C) 2013 Optical Society of America

A CMOS voltage reference without resistor is designed and simulated in SMIC 0.18μm CMOS process in this paper. Simulation results show that the power supply rejection (PSRR) of the voltage reference at 10Hz, 100kHz and 10MHz achieves, respectively, 44dB, 44dB and 37dB. When temperature is in range from -50 to 99°C, the voltage reference achieves an output voltage of about 1.21V with a variation of ±25mV.

A spectrum-splitting and beam-concentrating (SSBC) diffractive optical element (DOE) for three-junction photovoltaics (PV) system is designed and fabricated by five-circle micro-fabrication. The incident solar light is efficiently split into three sub-spectrum ranges and strongly concentrated on the focal plane, which can be directly utilized by suitable spectrum-matching solar cells. The system concentration factor reaches 12×. Moreover, the designed wavelengths (450 nm, 550 nm and 650 nm) are spatially distributed on the focal plane, in good agreement with the theoretical results. The average optical efficiency of all the cells over the three designed wavelengths is 60.07%. The SSBC DOE with a high concentration factor and a high optical efficiency provides a cost-effective approach to achieve higher PV conversion efficiencies.

A diode-end-pumped Q-switched high-efficiency Nd,Cr:YAG laser with simultaneous dual-wavelength emission at 946nm and 1.3 μm is demonstrated. The maximum output power of 1.93 W with simultaneous dual-wavelength operation is achieved at an absorbed pump power of 13.32 W and an absorbed slope efficiency of 15.15%. The maximum optical-optical efficiency is 14.49% with pulse widths of 16.38 ns at 946 nm and 26.65 ns at 1.3 μm. A maximum total repetition rate of 43.25 kHz is obtained.

We report the experimental results on improving the detection of an ultraweak optical signal using a 355 nm pumped picosecond collinear optical parametric amplification (OPA). The OPA is seeded by the amplified spontaneous emission (ASE) generated in a solution of pyridine-1 dye in ethanol. The gain factor of this amplifier is determined as ~1.5×10(8), and the detection limit is ~1.25 aJ per pulse, corresponding to five photons at 710 nm within the 15 ps pulse width of the pump beam. This is achieved by reducing superfluorescence background noise by means of signal/idler double seeding near degeneracy, amplification under a slightly phase-mismatched condition, and space filtering with increasing observation distance up to 3.2 m. Compared with previous reports, the detection limit is significantly enhanced. The pulse shape of the ASE is also measured with OPA, and it agrees well with that measured by an ultrafast oscilloscope.

An optimal thenar palmprint classification model is proposed in this paper. Firstly, the thenar palmprint image is enhanced using a high-frequency emphasis filter and histogram equalization. Then, from the enhanced image thirteen textural features of gray level co-occurrence matrix (GLCM) are extracted as classification feature vectors. Finally, the SVM classifier is used for classification and the best classification model will be obtained through comparing the classification results of different kernel functions and feature vectors. The experimental results proved the feasibility and effectiveness of this model for thenar palmprint classification.

The disadvantages of the Fast Thinning Algorithm and Improved OPTA Thinning Algorithm, i.e. incomplete thinning, not smooth and burr were analyzed and studied. The serial algorithm based on 4-connectivity parallel thinning was presented which had the advantage of quick speed and complete thinning. The lookup tables method was introduced in order to improve the operation speed. The thinned thenar palm print skeleton is smooth, no burr and located in the center of the ridge. The result of experiment is perfect.

The minimally invasive percutaneous plate osteosynthesis (MIPPO) technique through the anterior approach has been successfully used in the treatment of humeral shaft fractures and has gained satisfactory clinical outcome. An anatomical study and a preliminary clinic report were performed to evaluate the feasibility of applying the MIPPO technique in the treatment of humeral shaft distal fractures through the lateral approach. This study was done on 14 arms from seven fresh cadavers. The results of this study showed that it is possible to treat humeral shaft distal fractures by using the MIPPO technique through the lateral approach. The results of using the MIPPO technique through the lateral approach in the treatment of humeral shaft fractures in 22 patients were also reviewed.

We report on recent experimental results of the spontaneous antiphase dynamics that occurs in a laser-diode-pumped multimode passively Q-switched microchip Yb:YAG (where YAG is yttrium aluminum garnet) lasers with a saturable absorber GaAs. We observe that the pulse sequence of the first mode characterized by one, two, and three pulses as a group and all the modes display an antiphase state as the pumping ratio rises. We modify the multimode rate equations to account for nonlinear absorption due to GaAs in the presence of spatial hole burning. We perform numerical simulations based on the proposed rate equations and reproduce the observed antiphase state of two and three active modes.

Intra-articular fractures of the distal humerus are usually treated with cancellous screws for the condylar metaphysis itself and two Y-shaped plates for fixation of the metaphysis to the shaft. Twenty-four patients with comminuted intra-articular fractures (class C on AO/ASIF classification) were treated with crossed K-wires for the condylar metaphysis and double tension band osteosynthesis for fixation of the metaphysis block to the shaft. Excellent or good results were achieved in 83% of patients. This technique is easier to perform and more cost effective than most other fixation methods. Additionally, it offers good stability and allows for earlier functioning of the elbow. Complication rates are comparable to other methods of internal fixation.

We demonstrate the output characteristic of broadband parametric amplification of incoherent light pulses in a 355-nm pumped degenerate picosecond optical parametric amplification with either saturated or unsaturated amplification. The optical parametric amplifier is seeded by the fluorescence generated in a solution of pyridine-1 dye in ethanol. With the saturated amplification, we can obtain high energy incoherent light pulses, whose full width at half maximum bandwidth varies from 16 nm to 53 nm for the different phase matching angles near degeneracy. Moreover, the unsaturated bandwidth of the amplified pulses fits well to the calculated result at degeneracy. Selecting s-polarized fluorescence with a Glan—Taylor prism, the maximum bandwidth of the amplified fluorescence is found to be 59 nm for a purely s-polarized seed. The maximum output energy is 0.67 mJ for the optical parametric amplifier. By using an optical filter and compressor, the generated high energy incoherent light has great potential as the incoherent pump, signal or idler wave of a parametric down-conversion process, so that a wave with a high degree of coherence can be generated from an incoherent pump light.