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In order to effectively exploit the orbital angular momentum (OAM) characteristics, it is essential to have devices which are capable of generating beams with multiple OAM modes simultaneously. Most of the proposed techniques commonly require time division multiplexing at the transmitter side or beam splitters at the reception side for separating OAM modes and directing beams of different OAM modes to different directions. In order to overcome this problem, here, the concept of aperture sharing for generating concentrically embedded OAM carrying beams is presented. Such a methodology provides embedded beams of various OAM modes which are launched toward a single direction through a shared aperture of transmitarray (TA), while having a spatial division between them. In this manner, the transmitted beams are initially separated by the hardware at the transmitter level. A novel circularly-polarized (CP) substratecoupled unit-cell is designed and used as the elemental components on the aperture of the TA. Three prototype TAs are realized for investigating different cases of the OAM modes embedding and verifying the effectiveness of the proposed method. The obtained simulated and experimental results are consistent which validates the novel technique.

Modern optical fibers are capable of transmitting multiple wavelengths simultaneously using the wavelength division multiplexing (WDM) method for multiple–input multiple–output (MIMO) communication systems. They have been put to practical use by increasing the communication speed. This letter proposes a new WDM circuit that transmits and separates the TE $_{11x}$ , TE $_{11y}$ , and TM01 modes (polarization and multimodes) within a circular waveguide in the 5.6-GHz band. The transmission loss of each mode/polarization is up to 1.1 dB, and the isolation between modes/polarizations is more than 28.7 dB in a 200-mm-long circular waveguide. As a result, the independence of each mode and polarization applicable to MIMO communication systems is verified.

A broadband and compact TEO-TEI mode converter for a mode division multiplexing system designed using a wavefront matching method is realized. We present the first experimental demonstration of a silicon waveguide device designed by a wavefront matching method. In order to achieve broadband operation of the silicon mode converter, seven wavelengths are considered in its optimization process. The designed silicon mode converter is fabricated via a standard complementary metal-oxide-semiconductor technology, which enables low-cost mass production. Measurements performed using the fabricated mode converter correlate strongly with the calculated results. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

This article considers possible ways to reduce the time of air space survey by an onboard radar station in comparison with the known «classical» methods. The main direction of the proposals is related to the division of the entire sector of the airspace survey into severalrange zones. The division of the survey sector into three zones in accordance with the classification of the range of air-to-air missiles is justified. The calculation of the time of review of a given area of airspace for the proposed methods and comparison with the time of review of a similar zone with a needle beam, which showed the possibility of reducing the review time to two times, mainly when viewing the near and middle zones.The possibility of using different beams for radiating and receiving signals is considered.

In this study, the effects of facet reflectivity on the data erasure ability of injection-locked Fabry Perot Laser Diode (FPLD), based on a remodulation method in wavelength division multiplexed pa...

We propose a method to enlarge the field of view (FOV) of holographic 3D displays in both the horizontal and vertical directions. The FOV was enlarged by using two galvano mirrors and a high-speed spatial light modulator. These optical elements were placed so that the imaging relation was satisfied among them and they were synchronously driven at a high speed to implement the time-division method. Using this method, a floating 3D object could be successfully reconstructed in mid-air near the focal point of the final lens at the rate of 10 Hz. The FOV was enlarged five times and two times in the horizontal and vertical directions, respectively.

Benefiting from two-wavelength information multiplexed into one hologram, two-wavelength off-axis holography can perform simultaneous quantitative phase imaging in an extended thickness range. However, its present phase processing still adopts the traditional Fourier-based method at the expense of the reconstruction speed. Hence, we propose a fast approach by combining critical sampling with division multiplexing. In our approach, the critical sampling is used to remove the redundant data, and the division multiplexing is developed to eliminate the redundant calculation processes. Experimental results illustrate that our approach can yield faster reconstruction with frame rates up to 46 fps even for one megapixel multiplexed holograms at two wavelengths on a single-core personal computer.

A method of color holographic display from computer-generated cylindrical hologram (CGCH) based on radial-division is proposed. A single phase-only CGCH is calculated by using a multi-cylindrical surface (MCS) based iterative algorithm. This algorithm allows calculating a phase CGCH from red, green and blue components of a color object simultaneously. The radial distances for red, green and blue component objects are calculated according to the ratio of RGB wavelengths. When the hologram is illuminated by three laser beams of RGB colors, it can then reconstruct the wanted RGB components on the same radial position to obtain a color compound. Numerical simulation results demonstrate that simple 3D object can be reconstructed from single phase-only CGCH at the expected position.

In an indoor positioning system with numerous light emitting diodes (LEDs), one of the most critical issues that must be addressed is the design of a suitable layout for numerous LEDs. In the layout design, the neighbor interference and the long time delay are two of the main factors that limit the positioning accuracy of a moving device. In this study, we propose a novel layout design method of topological block network structure (BNS) based on time and space division multiplexing (TSDM) to accurately locate a large number of moving objects in an indoor environment under the condition of meeting lighting requirement. Performance indicator, the positioning accuracy, was focused on in this paper. The simulation results showed that with a suitable distance between adjacent LEDs adapted to the room height, the various illumination standards can be satisfied and the system time delay can be reduced to less than 500 ms. The results further demonstrated that positioning accuracy of less than 1 cm can be achieved by employing our BNS and TSDM scheme in 2D and 3D positioning algorithm with dimensions of 25 m by 25 m by 3 m.

A super-multiview light-field display with horizontal and vertical parallax is realized by time-division and color multiplexing to deliver full-color images to each viewpoint. In the conventional study, an image of a different color is delivered to each viewpoint to induce focal accommodation. In the proposed method, we deliver images of different colors sequentially to generate a full-color image by an after-image effect. Though the number of time-divisions increases in the proposed method, perceived flicker is suppressed by showing different colors at different timings. We compare the observed images given by the proposed method with those given by the conventional method to find out that the former reproduces a natural blur effect when the image is defocused. We also confirm with a psychophysical experiment using a refractometer that the proposed method induces a stronger focal accommodation than other super-multiview methods with a smaller number of time-divisions or with a stronger flicker. The proposed optics is applicable to a near-eye display with a natural focal effect.

Based on the principle of acousto-optic tunable filter and aperture division, the new method that can obtain a high spectral full polarization and image information was proposed. It was improved the accuracy of target detection and object recognition by this method. The Optical system of polarization imaging spectrometer based on aperture divisionandacousto-optic tunable filter was designed in this paper, which was used in the 2.16-meter telescope and spectral range is 450-900 nm .First,the working principle of polarization imaging spectrometer based on aperture division was introduced.Then, the design scheme of optical system and the principle of information acquisition were studied.Finally, the design parameters were assigned and theoptical systems were designed.The whole system MTF reach 0.6 in 32lp/mm.The olarization imaging spectrometer based on aperture division can improve the observation capacity.

We demonstrated the novel quasi-distributed optical fiber sensor with tens of cm spatial resolution based on the wavelength-division resonance frequency mapping technique. To interrogate a weak fiber Bragg grating (FBG) array with a reduced interval length below ~1 m, a wavelength-division optical delay system was employed to separate the adjacent reflections. In our scheme, the sensing head consists of three Bragg wavelengths in the FBG series, which are repeatedly located 15 times along the optical fiber. Thus, 45 weak FBGs can be successfully interrogated using three channels without decreasing the dynamic range of the measured strain or temperature.

"The astronomical community finds great utility in broadband medium resolution spectroscopy. Since its com- missioning, X-shooter has been one of the most heavily over-subscribed instruments on the VLT. To increase the availability of such facilities, the Son Of X-shooter instrument is being built for the NTT. Here we present the BRoadband Optical NIR COncept (BRONCO). This design is inspired by the novel SOXS visual arm, which splits the optical band into four sub-band and images them onto a single detector. BRONCO is a design for an 8.2m class telescope, and improves on the original design in several key ways: improved division of the bands, implementing it for a NIR arm and covering 0.32-1.8 um at resolution ~4500 for a 0.811 slit. Moreover we show an improved catadioptric camera design which uses the corrector in double pass, greatly simplifying the detector mounting and mechanics. Due to its optimized design BRONCO is expected to have throughput > 60%, excluding telescope and detector efficiencies-roughly 50% - 100% higher than X-shooter."

In this experiment we will find that the wavelength of light from a laser can be measured fairly well with the clever use of a ruler. This is a fine way to introduce more advanced forms of error propagation, as well as some introductory statistical analysis tools, to students in an upper division physics lab who are looking to understand the appropriate ways to interpret and report data. The evaluation methods used come directly from John R. Taylor’s ”An Introduction to Error Analysis”

The multi-spectral 3D display technology applies left and right lenses coated with multi-layer dielectric film to separate light waves with different wavelengths and then realize three-dimensional watching effect for audience. This paper has developed two spectral division films of 3D glasses, which are coated on left and right lenses of 3D glasses to reach “T≥85%” under waveband range of 421~438nm, 486~521nm and 575~619nm for left lens and under waveband range of 455~463nm, 540~550nm and 640~700nm for right lens and “T

Spectral self-imaging is induced on a frequency comb using a novel power-efficient XPM-based time-lens design. We demonstrate FSR division factors of 12 requiring pump powers 6 dB below that for the conventional parabolic time-lens.

Here we design a compact, portable and cost-effective holographic microscope based on the concept of holographic microscope slide. We developed a wavefront division holographic interferometer deployable for in-situ environmental monitoring and point-of care diagnostics.

In this paper, we propose a simple optical system that eliminates the 0th-order light by expanding the viewing angle by time division using multiple reconstructed illumination lights for one LCD.

We propose and analyze pre-chirp managed divided pulse amplification based on composite birefringent plates for pulse division and combination. Yb-fiber system using this technique can deliver

In recent years, with the continuous progress of science and technology, as two-dimensional display gradually cannot meet the needs of people, they began to seek the development of three-dimensional display equipment. There are mainly two kinds of naked eye stereoscopic display schemes: one is to use parallax barrier, the other is to use lenticular grating. In this paper, a new directional backlight scheme using a combination of lenticular grating and parallax barrier with blue light LED and phosphor layer is introduced. The existing multi-view naked eye stereoscopic display mostly adopts the straight down white light LED backlight, with the principle of time division, the left and right luminous units are lit up successively, so that the left and right eyes can see the left and right pictures, respectively. However, due to the large volume of the existing packaged white light LED, it is not easy to set up more groups of luminous units, which limits the number of viewers. Moreover, the diffusion film used in the white light scheme has a certain loss of light energy. The existing white light LED response speed is slow and you will see the phenomenon of residual shadow. In this paper, blue light LED has a small volume and we can set up more groups of luminous units within a limited size. Moreover, the phosphor film we made can play the role of diffusion film and make the original structure simpler.

An efficient method to remove carrier and aberration during phase processing from off-axis holography is proposed using a specimen-free hologram (SFH). One modulated carrier hologram (MCH) and one SFH are firstly encoded into a synthetic hologram. The synthetic hologram is then Fourier transformed, and the two cross-correlation orders can be obtained from its spectrum using two band pass filters. After implementing inverse Fourier transform, we can achieve the results containing phase distribution, carrier information, and aberration phase both of MCH and SFH. Through a division operation, the expected phase distribution can be retrieved without the information of carrier error and aberration. Simulations and experiments are carried out to demonstrate the validity of the method. Both results demonstrate that the new method can provide an accurate reconstruction with a superior retrieval speed.

The performance of a hard X-ray split-and-delay optical system with a wavefront division scheme has been investigated at SACLA., The performance of a hard X-ray split-and-delay optical (SDO) system with a wavefront division scheme was investigated at the hard X-ray free-electron laser facility SACLA. For the wavefront division, beam splitters made of edge-polished perfect Si(220) crystals were employed. We characterized the beam properties of the SDO system, and investigated its capabilities for beam manipulation and diagnostics. First, it was confirmed that shot-to-shot non-invasive diagnostics of pulse energies for both branches in the SDO system was feasible. Second, nearly ideal and identical focal profiles for both branches were obtained with a spot size of ∼1.5 µm in full width at half-maximum. Third, a spatial overlap of the two focused beams with a sub-µm accuracy was achieved by fine tuning of the SDO system. Finally, a reliable tunability of the delay time between two pulses was confirmed. The time interval was measured with an X-ray streak camera by changing the path length of the variable-delay branch. Errors from the fitted line were evaluated to be as small as ±0.4 ps over a time range of 60 ps.

In high power laser facility, the waveform measurement of UV pulse injected to target is very important for power balanced control and experiment result analysis. A time division multiplex UV frequency modulation pulse waveform measurement system based on fiber bundle and lens array is built for a high precise measurement result as well as low construction and maintaining cost. The system can remarkably improve coupling efficiency inject to fiber contribution to the aperture splicing sampling technology and a 50μm multi-mode UV fiber specially developed with 9.2GHz bandwidth@60m transmission. A “four-in-one” time division multiplex measurement system is built for laser facility and the practical experiment indicated that the system can realize precise waveform measurement within good economy and anti-interference performance.

We present a spatial light modulator (SLM) assisted compact holographic method and illustrate its application by imaging through a random scattering medium. The merit of the proposed method is wavefront division multiplexing, i.e. the dual wavefront modulations over a single SLM. Two different wavefront shapes: a reference-light shape and a phase object, are combined over the SLM. One advantage of this scheme is the flexible modulation of the reference light. The experimental implementation of this method is demonstrated by quantitatively reconstructing different phase objects from the randomly scattered light. This new scheme greatly simplifies the experimental configuration and presents a better stability even in presence of external vibrations, opening avenues for the holography-based scattering imaging application.

We propose a novel algorithm that does not require any Fourier transform to extract multiple object waves in a single image recorded with spatial frequency-division multiplexing. Smoothing is utilized to extract the desired object-wave information from a spatially multiplexed image. Numerical and experimental results show its validity and applicability for image and Fresnel digital holography. Our investigations clarify the speeding up of both the object-wave extractions and multiple object–image reconstructions quantitatively.

We propose a dual-wavelength phase-shifting digital holography technique with four wavelength-multiplexed holograms based on phase-division multiplexing utilizing the 2π ambiguity and zeroth-order diffraction-image suppression. Zeroth-order wave suppression is implemented by introducing the averaging method. Its effectiveness is experimentally shown and numerically and quantitatively investigated. The numerical investigation demonstrates the tolerance of the proposed technique against incoherent light noise and changes in the reference wave intensity. The image quality in the proposed technique depends on the intensity ratio between the object and reference waves but does not degrade with constant changes in intensity. In contrast, a previously reported four-step dual-wavelength phase-shifting technique was affected by the factors described above.

In this paper, we present two novel “quasi-Bayer” micro-polarizer (MP) patterns for the polarization imaging based on the division-of-focal-plane polarimeters (DoFP). Compared with the traditional equally-weighted MP pattern with four different micro-polarizers, the “quasi-Bayer” pattern requires less photo-lithography-based selective etching steps, leading to a significant reduction of the MP array's fabrication complexity. In addition, for the mainstream bilinear interpolation algorithm, the proposed “quasi-Bayer” pattern with three micro-polarizers exhibits the lowest mean square error (MSE) of 0.43%. Moreover, the “quasi-Bayer” patterns take advantages not only at the fixed illumination level, but also for different illumination levels. Reported experimental results validate the effectiveness of the “quasi-Bayer” patterns by varying the input light intensity from 13 lx to 213 lx.

We demonstrate an all few-mode fiber passively mode-locked figure-8 cavity laser. The hand-made mode division multiplexing-mode selective coupler makes it possible for LP11 mode at 976 nm to be used as pump light source.

In the measurement process of photoelectric scanning measurement network, the laser surface edge area has lower measurement accuracy than the middle area due to the geometrical distortions of the laser surface of the transmitter. This paper presents a sub-regional calibration method that can accomplish error compensation for the measurement system. Unlike the camera sub-regional calibration, the regional division and identification of the laser surface are more difficult. In this paper, the pitch angle in the transmitter coordinate frame of the spatial point was used as the basis for the division and identification of the laser surface. In the calibration process, the laser surface of the transmitter was divided into different regions and each region was calibrated independently, so that an intrinsic parameters database containing the intrinsic parameters of different regions could be established. Based on the database, the region identification and error compensation algorithm were designed, and comparison experiments were carried out. With the novel calibration method, the measurement accuracy of the system had an obvious upgrade, especially at the edges of the laser surface within a certain measurement area, which could enlarge the effective measurement area of the transmitter and would broaden and deepen the application fields of photoelectric scanning measurement network.

[EN] We report a model to use to evaluate the performance of multiple quantum key distribution (QKD) channel transmission using spatial division multiplexing (SDM) in multicore (MCF) and few-mode fibers (FMF). This model is then used to analyze the feasibility of QKD transmission in 7-core MCFs in two practical scenarios involving the (1) transmission of only QKD channels and (2) simultaneous transmission of QKD and classical channels. In the first case, standard homogeneous MCFs enable transmission distances per core compatible with transmission parameters (distance and net key rate) very close to those of single-core single-mode fibers. For the second case, heterogeneous MCFs must be employed to make this option feasible., European Regional Development Fund (ERDF); Galician Regional Government (project GRC2015/018 and agreement for funding AtlantTIC (Atlantic Research Center for Information and Communication Technologies)); European Research Council (ERC) (Consolidator Grant 724663); Spanish MINECO (TEC2016-80150-R project and Ramon y Cajal fellowship RYC-2014-16247 for I. Gasulla).

This publisher’s note identifies an error in Appl. Opt. 60, 1966 (2021)APOPAI0003-693510.1364/AO.413352.

We propose a high-speed playback method for the spatiotemporal division multiplexing electroholographic three-dimensional (3D) video stored in a solid-state drive (SSD) using a digital micromirror device. The spatiotemporal division multiplexing electroholography prevents deterioration in the reconstructed 3D video from a 3D object comprising many object points. In the proposed method, the stored data is remarkably reduced using the packing technique, and the computer-generated holograms are played back at high speed. Consequently, we successfully reconstructed a clear 3D video of a 3D object comprising approximately 1,100,000 points at 60 frames per second by reducing the reading time of the stored data from an SSD.

In this paper, a distortion correction method with reduced complexity is proposed. With the singleparameter division model, the initial approximation of distortion parameters and the distortion center can be calibrated. Based on the distance from the image center to the fitting lines of the extracted curves, a bending measurement function with a weighted factor is proposed to optimize the initial value. Simulation and experiments verify the proposed method.

The circular lobed nozzle used in the infrared suppressors of helicopters and warships has a configuration that facilitates highly effective mixing of the jet. A sword alternating-lobe nozzle and two types of spoilers (installed at the lobe peaks to improve the mixing) were introduced. In this study, numerical investigations of the jet mixings of different nozzle configurations were conducted. The nozzles considered were a baseline lobed nozzle, a baseline lobed nozzle with a central plug, a coplanar alternating-lobe nozzle, a sword alternating-lobe nozzle, and a sword alternating-lobe nozzle with lobe-peak spoilers. The dominant factors that affect the pumping performance, mixing effectiveness, and pressure loss were also analysed. It was found that, in addition to the intensity of the streamwise vortices and the distribution of the primary stream, the distribution of the streamwise vortices is also strongly related to the mixing effectiveness and determined the formation of new and plumper streamwise vortices, which improved the mixing effectiveness. The division into three segments of the side of the streamwise vortices on which the primary and secondary streams contact each other is propounded. The three segments are the windward, sideward, and leeward segments. The windward segment has the fastest mixing, followed by the sideward segment, while the leeward segment has the slowest mixing. The plumper streamwise vortices enhance mixing because their windward segment is longer.

Generation of digital phase-only Fresnel holograms is an important research area in digital holography, as it leads to a substantial simplification of a holographic display system. However, the quality of the reconstructed image of a hologram without the magnitude component is heavily degraded. The problem can be reduced by down-sampling the intensity of an image prior to generating the hologram. The method, referred to as &ldquo, sampled phase-only hologram&rdquo, (SPOH) generation, results in reconstructed images that are masked with the pattern of the down-sampling lattice. This paper reports a novel, low complexity method to alleviate this problem through the concept of comb filtering. Results reveal prominent enhancement on the reconstructed image of a SPOH.

Computationally, the calculation of computer-generated holograms is extremely expensive, and the image quality deteriorates when reconstructing three-dimensional (3D) holographic video from a point-cloud model comprising a huge number of object points. To solve these problems, we implement herein a spatiotemporal division multiplexing method on a cluster system with 13 GPUs connected by a gigabit Ethernet network. A performance evaluation indicates that the proposed method can realize a real-time holographic video of a 3D object comprising ∼1,200,000 object points. These results demonstrate a clear 3D holographic video at 32.7 frames per second reconstructed from a 3D object comprising 1,064,462 object points.

We have developed a single-shot imaging technique that can capture ultrafast events occurring on femtosecond to picosecond time scales. The technique is based on an optical pump-probe method, in which multiple time-delayed femtosecond pulses simultaneously probe a pump-excited sample. Here we use two sets of 2-by-2 mirror arrays for spatial/temporal division and routing of multiple probe pulses. This single-shot scheme is successfully applied to capture femtosecond ionization fronts propagating at the speed of light in air, as well as laser-induced ablation of solid targets., 17 pages, 5 figures

A hand gesture monitoring system based on fiber-optic curvature sensors is developed. A glove is used as a carrier to support the monitoring system. According to the freedom of the hand joint, the layout of the sensors is established. An untreated fiber is introduced as a reference signal. The division operation between the sensing signal and reference signal is regarded as the monitoring result, which can reduce the monitoring error produced by external unstable factors. The experimental results show that the measurement errors are within the range of ±π/36 and ±π/75, respectively, when measuring the joint bending and abduction angle, which indicates the feasibility of the proposed monitoring system.

At consideration of the theory of the Michelson’s experiment and conducting experiments on its scheme of dividing the amplitude of the light flux as an informative parameter, the difference in the lengths of the paths of the transverse and longitudinal rays of the light flux is used by measuring the shift of the interference pattern of the transverse and longitudinal rays. The significance of the other circuit parameters in determining the influence of the Earth's speed with the help of Michelson interferometers was not considered. The analysis of the parameters of the schemes of Michelson interferometers with the division of both the wave front amplitude and its wave front in the reference system associated with the interferometer is carried out in order to determine the influence of the interferometer speed on them. As a result of the analysis of the scheme with the division of amplitude, a linear dependence of the changes in frequency, the width of the reflected rays on the ratio of the device speed to the speed of light in interferometers. In the Michelson interferometer scheme with wave front division, the difference of paths length and the ray deflection angles are linearly dependent on the ratio of the device speed to the speed of light .These additional dependences are determined by the collinearity of the reflected rays and the speed of the observer's movement, in contrast to their perpendicularity in the interferometer with the division of the wave front amplitude. As a result of the comparison of the parameters in the reference system associated with the interferometer, it is concluded from their significance that the use of frequency changes, the width of the reflected rays in the interferometer with amplitude division, and the wave front interferometer, the difference in the path lengths of the rays, frequency, angle of deflection and the width of the reflected rays is preferable.

In this study, the use of PLC (Planar Lightwave Circuit) splitter in bi-directional WDM optical systems instead of the standard WDM (Wavelength Division Multiplex) splitters is theoretically described and practically confirmed in real telecommunications environment. The transmission of two optical signals in opposite direction over a single mode fiber is tested at slightly spaced wavelengths. The insertion and separation of opposite optical signals are realized using two 1:2 PLC splitters. The measurements are successfully completed for two different lengths of optical fibers (8055 and 61091 m). The proposed solution is cost-effective and flexible, with a wide temperature range covering a broad band of operating wavelengths.

International audience; Digital holographic microscopy is the state of the art quantitative phase imaging of micro-objects including living cells. It is an ideal tool to image and quantify cell thickness profiles with nanometer thickness resolution. Digital holographic techniques usually are implemented using a two-beam setup that may be bulky and may not be field portable. Self-referencing techniques provide compact geometry but suffer from a reduction of the field of view. Here, we discuss the development of a wavefront division digital holographic microscope providing the full field of view with a compact system. The proposed approach uses a wavefront division module consisting of two lenses. The developed microscope is tested experimentally by measuring the physical and mechanical properties of red blood cells.

We demonstrated the mode-group demultiplexing technique based on a volume holographic demultiplexer (VHDM) for mode-group division multiplexing transmission using multi-mode fibers. In the experiment, the VHDM achieved the separating of three mode-group channels with a single holographic recording medium. Thus, the modal cross-talk was obtained as −14.7 dB.

An effective approach for reconstructing on-axis lensless Fourier Transform digital hologram by using the screen division method is proposed. Firstly, the on-axis Fourier Transform digital hologram is divided into sub-holograms. Then the reconstruction result of every sub-hologram is obtained according to the position of corresponding sub-hologram in the hologram reconstruction plane with Fourier transform operation. Finally, the reconstruction image of on-axis Fourier Transform digital hologram can be acquired by the superposition of the reconstruction result of sub-holograms. Compared with the traditional reconstruction method with the phase shifting technology, in which multiple digital holograms are required to record for obtaining the reconstruction image, this method can obtain the reconstruction image with only one digital hologram and therefore greatly simplify the recording and reconstruction process of on-axis lensless Fourier Transform digital holography. The effectiveness of the proposed method is well proved with the experimental results and it will have potential application foreground in the holographic measurement and display field.

We propose and investigate two-dimensional spatial coherent matched detection using high-speed photodiode array. Without optical spatial filtering/splitting, all mode-division multiplexed (MDM) channels are coherently demultiplexed and detected, ideally yielding 3-dB optical loss for any MDM signals.

A new experimental chamber has been installed at the 3 MV Van de Graaff Accelerator Facilities Division in the Atomic Energy Centre, Dhaka, to perform different Ion Beam Analysis (IBA) techniques. The calibration of this new setup for Particle Induced X-ray Emission (PIXE) technique has been done using a set of thin MicroMatter standards and GUPIX (PIXE spectrum analysis software), which is explicated in this paper. The effective thicknesses of the beryllium window of the X-ray detector and of the different absorbers used were determined. For standardization, the so called instrumental constant H (product of detector solid angle and the correction factor for the setup) as function of X-ray energy were determined and stored inside the GUPIX library for further PIXE analysis.

A new method of projection of color images without color-sequential technique is proposed. It is a combination of the spatial division of the phase-only light modulator with a pixel separation noise suppression technique and an efficient propagation method called a scaled Fresnel diffraction. The unique property of a step-less and lossless zooming of the projected image is shown. The experimental demonstration of the method is presented, showing high quality, low noise images of a variable size at reasonable frame rates.

The wavefront printer records a volume-reflection hologram as a two-dimensional array of elemental holograms from computer-generated holograms (CGHs) displayed on a spatial light modulator (SLM). The wavefront coming from the object is extracted by filtering in the spatial-frequency domain. This paper presents a method to improve color reproduction in a wavefront printer with spatial division of exposures at primary colors, by adaptive partitioning of the SLM in accordance with the color content encoded in the input CGHs, and by the controllable change of exposure times for the recording of primary colors. The method is verified with a color wavefront printer with demagnification of the object beam. The quality of reconstruction achieved by the proposed method proves its efficiency in eliminating the stripe artifacts that are superimposed on reconstructed images in conventional mosaic recording.