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Du Y.,University of Sichuan | Feng G.,University of Sichuan | Li H.,University of Sichuan | Vargas J.,CSIC - National Center for Biotechnology | And 2 more authors.
Optics Express | Year: 2012

A non-iterative spatial phase-shifting algorithm based on principal component analysis (PCA) is proposed to directly extract the phase from only a single spatial carrier interferogram. Firstly, we compose a set of phase-shifted fringe patterns from the original spatial carrier interferogram shifting by one pixel their starting position. Secondly, two uncorrelated quadrature signals that correspond to the first and second principal components are extracted from the phase-shifted interferograms by the PCA algorithm. Then, the modulating phase is calculated from the arctangent function of the two quadrature signals. Meanwhile, the main factors that may influence the performance of the proposed method are analyzed and discussed, such as the level of random noise, the carrierfrequency values and the angle of carrier-frequency of fringe pattern. Numerical simulations and experiments are given to demonstrate the performance of the proposed method and the results show that the proposed method is fast, effectively and accurate. The proposed method can be used to on-line detection fields of dynamic or moving objects. ©2012 Optical Society of America.


Du Y.,University of Sichuan | Feng G.,University of Sichuan | Li H.,University of Sichuan | Vargas J.,CSIC - National Center for Biotechnology | And 2 more authors.
Optics Letters | Year: 2012

A simple and compact point-diffraction interferometer with circular common-path geometry configuration is developed. The interferometer is constructed by a beam-splitter, two reflection mirrors, and a telescope system composed by two lenses. The signal and reference waves travel along the same path. Furthermore, an opaque mask containing a reference pinhole and a test object holder or test window is positioned in the common focal plane of the telescope system. The object wave is divided into two beams that take opposite paths along the interferometer. The reference wave is filtered by the reference pinhole, while the signal wave is transmitted through the object holder. The reference and signal waves are combined again in the beam-splitter and their interference is imaged in the CCD. The new design is compact, vibration insensitive, and suitable for the measurement of moving objects or dynamic processes. © 2012 Optical Society of America.


Yang H.,University of Sichuan | Feng G.,University of Sichuan | Zhou S.,University of Sichuan | Zhou S.,North China Research Institute of Electro Optics
Optics and Laser Technology | Year: 2011

An investigation of thermal effects in a high-power Nd:YAG disk-type solid state laser pumped with different pump beam transverse profiles is carried out by numerical simulation based on the finite element method (FEM). Impact of the heat sink on the thermal effects is included in the simulation. The distribution of first principle stress, thermally induced birefringence, including the distribution and variation of the birefringence loss, are studied. The characteristics of the phase variation are analyzed with consideration of the temperature gradient, deformation, strain and thermal stress. Thermal lensing is explored as a function of pump power and of the radius pumped with different pump beam transverse profiles. The non-parabolic part of optical phase distortion is simulated. Furthermore, the characteristics of the bi-focus of the disk laser are also studied. Experiments on the maximum tensile stress distribution and depolarization loss are carried out. The presented calculations are in qualitative agreement with the experimental observations. © 2011 Elsevier Ltd. All rights reserved.


Zhou H.,University of Sichuan | Feng G.,University of Sichuan | Yao K.,University of Sichuan | Yang C.,University of Sichuan | And 3 more authors.
Optics Letters | Year: 2013

We investigate a tunable fluidic dye laser formed by a microcavity filled with a dye solution. We achieve a wide 18 nm tunability of the laser wavelength by controlling the cavity length for the first time. The microcavity is made of a silica capillary and two aligned fibers with end faces Au-coated. The Rhodamine 6G dye solution flowing through the microcavity is pumped by 532 nm wavelength laser pulses. Laser emission around 570 nm in the form of TE mode with a threshold of about 58 μJ/pulse is obtained. This work suggests a fiber-based convenient approach to achieve wavelength tunability and integration with lab-on-a-chip systems. © 2013 Optical Society of America.


Wang S.,University of Sichuan | Feng G.,University of Sichuan | Zhou S.,University of Sichuan | Zhou S.,North China Research Institute of Electro Optics
Applied Physics Letters | Year: 2014

Micro/nano patterning of ZnSe wafer is demonstrated by femtosecond laser irradiation through a diffracting pinhole. The irradiation results obtained at fluences above the ablation threshold are characterized by scanning electron microscopy. The microsized structure with low spatial frequency has a good agreement with Fresnel diffraction theory. Laser induced periodic surface structures and laser-induced periodic curvelet surface structures with high spatial frequency have been found on the surfaces of microsized structures, such as spikes and valleys. We interpret its formation in terms of the interference between the reflected laser field on the surface of the valley and the incident laser pulse. © 2014 AIP Publishing LLC.


Fu Y.,CAS Shanghai Institute of Ceramics | Li J.,CAS Shanghai Institute of Ceramics | Liu Y.,North China Research Institute of Electro Optics | Liu L.,North China Research Institute of Electro Optics | And 2 more authors.
Optical Materials Express | Year: 2014

2.0at.% Nd:YAG transparent ceramics were prepared by a solidstate reactive sintering method. The as-sintered specimens were annealed at different temperatures for different time. The ceramics with average grain size of 15μm are dense and homogeneous in structure. 1450°C is determined as the optimum annealing temperature and the annealing time longer than 5h is considered as the appropriate time by the optical spectra and laser performance. At this temperature and holding time, the concentration of color centers in the specimen is relatively low and the laser slope efficiency is the highest. It is concluded that less color centers and lower optical loss in Nd:YAG transparent ceramics are necessary to obtain the excellent laser performance. © 2014 Optical Society of America.


Luo S.-J.,North China Research Institute of Electro Optics | Xia Y.-H.,North China Research Institute of Electro Optics | Yang N.-N.,North China Research Institute of Electro Optics | Yu F.-D.,North China Research Institute of Electro Optics
Chinese Optics | Year: 2015

Using infrared scanning system principle, a novel long-wavelength continuous zoom scanning optical system is presented based on 4×288 infrared MCT detector dewar cooled assembly. Related optical index parameters are resolved and calculated according to requirements of system, and the optical design parameters and outside view are obtained by the optical design software. The narcissus effect of the scanning optical system are analyzed and optimized. The optical system is composed of zoom telescope, scanning mirror, relay lens, imaging lens and a tertiary imaging system including nine lenses and two reflectors. In order to reduce cost and optical color aberrations, chalcogenide glass lens is used. The optical index is simulated, and the MTF in whole field at Nyquist frequency is over 0.35 and distortion is below 2%.Finally the system imaging experimental verification is conducted. The results indicate that 30.8~154 mm continuous zoom and 100% cold shield efficiency are achieved. High resolution, thermal sensibility, excellent images are validated. ©, 2015, Editorial Office of Chinese Optics. All right reserved.


Yang L.,University of Sichuan | Feng G.,University of Sichuan | Yi J.,University of Sichuan | Yao K.,University of Sichuan | And 2 more authors.
Applied Optics | Year: 2011

We have studied the random laser action in Rhodamine 6G (Rh6G) ethylene glycol solution with Al nanoparticles. The experiment results are obtained by pumping with a nanosecond (7 ns) laser pulse, which demonstrated the existence of effective random laser emission. It is found that the threshold of the random laser depends on the concentration of the Rh6G and the concentration of Al nanoparticles. The concentration and diameter of Al nanoparticles have effects on the optical path; a higher concentration or a larger diameter results in a shorter optical path length. Also multimode survival and mode competition have been observed at a relatively high concentration (0:08 M) of Rh6G, where the concentration of Al nanoparticles is 0:0015 M. © 2011 Optical Society of America.


Luo S.-J.,North China Research Institute of Electro Optics | He W.-B.,North China Research Institute of Electro Optics | Li W.-H.,North China Research Institute of Electro Optics | Xu M.-X.,North China Research Institute of Electro Optics
Guangxue Jingmi Gongcheng/Optics and Precision Engineering | Year: 2012

A mid-wavelength continuous zoom optical system was presented for a staring Focal Plane Array (FPA) infrared detector by cooling assembly. The optical system with an optical configuration of reflect mirror fold was composed of a zoom object lens system and a secondary imaging system including seven lenses and two reflectors. On the basis of zoom principles, the systemic structure and design parameters were given by using special optical design software, then the schematic diagram and imaging quality were investigated. Finally, the performance and indexes of the system were verified. The results indicate that the system can offer a 50-500 mm continuous zoom and 100% cold shield efficiency. Moreover, the Modulation Transfer Function (MTF) in whole fields at Nyquist frequency is over 0.35 and the whole field distortion is below 2%. These results show that the system is characterized by high resolution, thermal sensibility, excellent images and smooth zoom locus.


Mao X.-J.,Science and Technology on Solid State Laser Labotatory | Mao X.-J.,North China Research Institute of Electro Optics
Chinese Optics | Year: 2015

High-power picosecond ultraviolet lasers have attracted considerable interests as novel laser source, due to their wide applications in high precision product, laser medical system, optoelectronic countermeasure and structuring of silicon. The research and development on high-power picosecond ultraviolet laser based on technology of sum frequency are classified and summarized. First, the mechanism of sum frequency and picosecond ultraviolet crystal are discussed. Then the high-power picosecond ultraviolet laser, the high-peak-power picosecond ultraviolet laser, and the high-power and high-peak-power picosecond ultraviolet lasers are discussed. Finally, the prospect of further development and applications of high-power picosecond ultraviolet laser sources is put forward. According to the latest development, it is indicated that the high power picosecond ultraviolet lasers developed in abroad is in maturity stage but just in starting stage at. The high-power picosecond ultraviolet lasers based on photonic crystal fiber laser and thin disk laser have some merits, which play important roles in laser industry. © 2015, Editorial Office of Chinese Optics. All right reserved.

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