Hu Dongxia   Tao Yudong   Ma Jingui   Wang Jing   Zhu Heyuan   Qian Liejia  

      摘要 + ：(浏览：5次) | 此论文可免费阅读 (可能需要登录)

Quasi-parametric chirped-pulse amplification (QPCPA) can improve the signal amplification efficiency and stability by inhibiting the back conversion, in which the idler absorption plays a critical role. This paper theoretically studies the impacts of idler absorption on the QPCPA performance in both the small-signal and saturation regimes. We demonstrate that there exists an optimal idler absorption that enables the achievement of maximum pump depletion within a minimum crystal length. To overcome the reduction in small-signal gain induced by idler absorption, the configuration of gradient idler absorption is proposed and demonstrated as a superior alternative to constant idler absorption. The results provide guidelines to the design of state-of-the-art QPCPA lasers.

       PDF全文 (下载：3)        Chinese Optics Letters ，2018年第16卷第12期 pp.12      

Zhang Zhiming   Wei Wei   Tang Liqin   Yang Jie   Guo Jiewei   Ding Lei   Li Yigang  

      摘要 + ：(浏览：23次) | 此论文可免费阅读 (可能需要登录)

An all fiber femtosecond vortex laser based on common fiber components is constructed. It can produce femtosecond orbital angular momentum modes whose pulse width of time is 398fs. The topological charge of output OAM modes from this setup can be adjusted among 0, +1, -1 easily while it is also easy to convert between continuous OAM modes and pulse OAM modes.

       PDF全文 (下载：7)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Yao Jie   Yu Ya-fei   Zhang Zhiming  

      摘要 + ：(浏览：25次) | 此论文可免费阅读 (可能需要登录)

We introduce a Casimir force in a conventional optomechanical system to study the high-order sideband generation. In this system, a nanosphere is placed nearby the moveable mirror of the conventional optomechanical system. The moveable mirror is coupled to the cavity field and the nanosphere by the optomechanical interaction and the Casimir interaction, respectively. We find that the amplitude and cutoff order of the high-order sideband can be enhanced by decreasing the sphere-mirror separation ( increasing the Casimir force) and increasing the optomechanical coupling strength. Our proposal provides an alternative method for generating the high-order sidebands, and for measuring the Casimir force.

       PDF全文 (下载：8)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Wang Feili   Lou Cibo   Liang Yi  

      摘要 + ：(浏览：24次) | 此论文可免费阅读 (可能需要登录)

We numerically investigate the propagation properties of ring Airy Gaussian beams (RAGBs) with cosine modulated optical vortices (CMOV). In comparison to the common RAGBs without any modulation, the dynamic propagation of RAGBs with CMOV exhibits a unique feature: the rings of RAGBs with CMOV will gradually shrink into several main lobes with the increase of the propagation distance. The number of lobes and the peak intensity of each lobe are determined by the factors of cosine modulated function. By designing the initial phase, we can easily change the transversal location of the peak intensity. Our results may find potential applications in optical manipulations.

       PDF全文 (下载：13)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Cui Peng   Zhang Wentao   Song Ying  

      摘要 + ：(浏览：14次) | 此论文可免费阅读 (可能需要登录)

In this paper, a vertical-pendulum-based inclinometer based on Fiber Bragg Grating Fabry-Perot (FBG-FP) cavity is proposed. A low-damping rotation structure is used to reduce the mechanical frictions of the pendulum system and induce wavelength shift of FBG-FPs. We find that the sensitivity can be maximized by optimizing the parameters of the inclinometer. Using high-resolution demodulation system, a sensitivity of 179.9 pm/° and a resolution better than 2.0×10-2 ″ can be achieved. Experiments also show that the proposed inclinometer has good linearity and repeatability.

       PDF全文 (下载：1)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Gao Wanli   Liu Guanyu   Zhang Zhigang  

      摘要 + ：(浏览：20次) | 此论文可免费阅读 (可能需要登录)

44.6 fs pulses from a 257 MHz, mode-locked non-PM Er-doped fiber laser based on biased nonlinear amplifying loop mirror (NALM) is reported. The output power is 104 mW and the single pulse energy is 0.4 nJ. The minimum pulse duration of the direct output is 44.6 fs, which is the shortest in this kind of laser.

       PDF全文 (下载：6)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Deng Suhui   Xiao Yiping   Hu Jie   Chen Jianfang   Wang Yuhao   Liu Mingping  

      摘要 + ：(浏览：18次) | 此论文可免费阅读 (可能需要登录)

The fluorescence from out-of-focus region excited by the side lobes of Bessel beam is the major concerns for the light-sheet fluorescence microscopy (LSFM) with Bessel beam plane illumination. Here, we propose a method of applying the subtractive imaging to overcome the limitation of the conventional LSFM with Bessel beam plane illumination. In the proposed method, the sample is imaged twice by line-scanning using the extended solid Bessel beam and the ring-like Bessel beam. By subtracting between the two images with similar out-of focus blur, the improved image quality with the suppression of the Bessel beam side lobes and enhanced sectioning ability with improved contrast is demonstrated.

       PDF全文 (下载：3)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Kang Kai   Zhang Liangliang   Wu Tong   Li Kai   Zhang Cunlin  

      摘要 + ：(浏览：16次) | 此论文可免费阅读 (可能需要登录)

We report the terahertz (THz) wave generation from single color scheme modulated by pre-ionized air plasma via an orthogonal pumping geometry. It is found that the amplitude of the THz signal generated by the pump beam tends to decrease gradually with the increase of the modulation power. We believe that the ponderomotive force plays an important role in the process of the interaction between the pump beam and pre-ionization beam. The hydrostatic state of the electrostatic separation field caused by modulation beam will directly affect the generation efficiency of the THz wave. Our results contribute to further understanding of the theoretical mechanism and expanding of the practical applications of terahertz THz wave generation and modulation.

       PDF全文 (下载：2)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

tianbo zhao   fenglan fan   ying liu   yifan hong   jinliang zang   guoguo kang   Tan Xiaodi  

      摘要 + ：(浏览：18次) | 此论文可免费阅读 (可能需要登录)

A novel composite materials are synthesized by incorporating N-acryloylmorpholine (ACMO) in highly-concentrated phenanthrenequinone (PQ) doped poly-(methyl methacrylate) (PMMA). The photosensitizer concentration of PQ was increased from 0.7wt% to 1.8wt%. The doping of ACMO component results in a higher diffraction efficiency and photosensitivity than typical PQ/PMMA system. The enhanced performance of material may stem from the ACMO molecules which might open a new route for improving the holographic performance of PQ/PMMA photopolymer..

       PDF全文 (下载：6)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Hua Jianwen   Whang Zhanhu   Duan Juan   Li Libing   Zhang Chengjun   Wu Xiaowei   Fan Qing   Chen Ren   Sun Xiaojie   Zhao Lianwei   Guo Qian   Ding Lei   Sun Liwei   Han Changpei   Li Xiangyang   Wang Nili   Gong Haimei   xiaoning Hu   Liao Qingjun   Liu Dingquan   Yu Tianyan   Wu Yinong   Liu Enguang   Zeng Zhijiang  

      摘要 + ：(浏览：20次) | 此论文可免费阅读 (可能需要登录)

To measure the global atmospheric 3-dimensional distribution and change of temperature and humidity is one of the key areas in atmospheric remote sensing detection, it is also a new research and development direction in the field of meteorological satellite application. As a main element of China second generation of geostationary meteorological satellite FY-4 which was launched on Dec.11, 2016, Geostationary Interferometric Infrared Sounder (GIIRS) is the first interferometric infrared sounder working on geostationary orbit internationally. It is used for vertical atmospheric sounding and gains atmospheric temperature, humidity and disturbances. The combination of Fourier transform spectrometer technology and infrared detectors make GIIRS to have high spectral resolution and large coverage over spatial areas. With this kind of instrument, meteorological satellites can improve the capabilities for severe weather event monitoring and numerical weather prediction. In this paper a concise review of the GIIRS development project, including its history, missions and functions, technical design, key technologies, system integration, calibration and in-orbit operation status, etc. is presented.

       PDF全文 (下载：5)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Xu Yongchi   Peng Huanfa   Guo Rui   Du Huayang   Hu Guoqing   Zhu Lixin   Chen Zhangyuan  

      摘要 + ：(浏览：48次) | 此论文可免费阅读 (可能需要登录)

A wideband tunable optoelectronic oscillator (OEO) based on a tunable single-bandpass microwave photonic filter (MPF) and a recirculating delay line (RDL) is proposed and experimentally demonstrated. The MPF is formed by cascading a finite impulse response filter and an infinite impulse response filter, which can enhance the quality-factor of the MPF and suppress the side modes of the OEO. Frequency response of the tunable MPF is theoretically analyzed. By placing the MPF into OEO, tunable microwave signal from 10.3GHz to 26.7GHz and 100MHz-step tunability are experimentally demonstrated. The phase noise is -113 dBc/Hz@10kHz. The results agree well with the theory.

       PDF全文 (下载：10)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Li Yiyu   Huang Wei   Feng Haihua   Chen Jiaojie  

      摘要 + ：(浏览：27次) | 此论文可免费阅读 (可能需要登录)

Astigmatism is inevitable and inherent to progressive addition lens (PAL), which are typically distributed in the lateral areas on both sides of progressive corridor. In this study, we took into account the spectacle frame for the customized freeform PAL design with the variational-difference numerical approach. PAL surface with minimized astigmatism, approximately equal to 84% of the add power, was numerically resolved without expending the zone for clear vision. We validated our approach by experimentally demonstrating the procedure from tool path generation to surface power measurement, thus providing an efficient solution to the personalization of astigmatism-minimized PAL design and manufacture.

       PDF全文 (下载：4)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Zhang Xiaotong   Yuan Tingting   Yang Xinghua   Guan chunying   Yang Jun   Liu Zhihai   Deng Hongchang   Yuan Libo  

      摘要 + ：(浏览：27次) | 此论文可免费阅读 (可能需要登录)

In-fiber integrated optics is an attempt to use silica fiber as a substrate, integrating various optical paths or optical components into a single fiber, to build a functional optical device or component, to realize a micro optical system, achieving various functions. In-fiber integrated optics is expected to be a new branch of photonics integration. This integration technique enables conve-nient light beams control and manipulation inside in one fiber. It also provides a research platform with micro and nano scale for interaction between lightwave and microfluidic maters. In this paper, we briefly summarize the main ideas and key technologies of the in-fiber integrated optics by series integration examples.

       PDF全文 (下载：3)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Deng Yangchun   Zhao Junlei   Dai Yun   Zhang Yudong  

      摘要 + ：(浏览：27次) | 此论文可免费阅读 (可能需要登录)

A simple and straightforward method to objectively measure the transverse chromatic aberration (TCA) at horizontal field angles out to ±10° from visual axis of the human eye was proposed. Longitudinal chromatic aberration (LCA) was also measured across the visual field. TCA of human eye was obtained by deviation of point-spread function (PSF) images. LCA was calculated from Zernike defocus. The average TCA changing with eccentricity was 0.162 arcmin/degree between 639 nm and 795 nm wavelengths. Near the optic axis of the eye, the average LCA was 0.37+/-0.02 D, and it increased slightly with eccentricity (up to 0.54+/-0.02 D).

       PDF全文 (下载：6)        Chinese Optics Letters ，2018年第16卷第11期 pp.11      

Tu Han-Yen   He Ssu-Chia  

      摘要 + ：(浏览：33次) | 此论文可免费阅读 (可能需要登录)

This paper describes a novel fringe-shaping technique developed to alleviate the fringe truncation problem engendered by the acquired saturated and/or weak fringe images from high-/low-reflectance surface of three-dimensional (3D) object in phase-shifting profilometry. Particle swarm optimization algorithm is employed to perform the recovery of the truncated fringes with the optimal fitting for compensation after a single-trial acquisition. The results show that the proposed method improves phase recovery accuracy to accomplish 3D surface reconstruction with only one set phase-shifting fringes of single-trial fringe projection under different truncation sceneries.

       PDF全文 (下载：3)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Luo Binbin   Lu Huafeng   Shi Shenghui   Zhao Mingfu   Lu Jiao   Wang Yajie   Wang Xing  

      摘要 + ：(浏览：30次) | 此论文可免费阅读 (可能需要登录)

We demonstrate a fiber refractive index (RI) sensor based on excessively tilted fiber grating (ExTFG) immobilized by large-size plasmonic gold nanosells(GNSs). The GNSs are covalently linked on ExTFG surface. Experimental results demonstrate that both the intensity of transverse magnetic (TM) and transverse electric (TE) mode of ExTFG are significantly modulated by the localized surface Plasmon resonance (LSPR) of GNSs due to the wide-range absorption band. The wavelength RI sensitivities of TM and TE mode in the low RI range of 1.333~1.379 are improved by ~25% and ~14% after GNSs immobilization, respectively, and the intensity RI sensitivities are ~599%/RIU and ~486%/RIU, respectively.

       PDF全文 (下载：4)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Lin Tiancheng   Wu Guiling   Li Hongwei   Wang Guoyong   Chen Jianping  

      摘要 + ：(浏览：34次) | 此论文可免费阅读 (可能需要登录)

We propose a passive compensation fiber-optic radio frequency (RF) transfer scheme with a nonsynchronized RF source stable during a round-trip time, which can avoid high-precision phase-locking and efficiently suppress the effect of backscattering only using two wavelengths at the same time. A stable frequency signal is directly reproduced by frequency-mixing at the remote site. The proposed scheme is validated by the experiment over a 40 km single mode fiber spool using nonsynchronized common commercial RF sources. The influence of the stability of nonsynchronized RF sources on the frequency transfer is investigated over different length fiber links.

       PDF全文 (下载：2)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Chang Chenliang   Qi Yijun   Wu Jun   Xia Jun   Nie Shouping  

      摘要 + ：(浏览：36次) | 此论文可免费阅读 (可能需要登录)

In liquid crystal spatial light modulator (LCoS-SLM) based holographic projection, the image is usually displayed at a distant projection screen through free space diffraction from a computer-generated hologram (CGH). Therefore, it allows to removing the projection lens for the sake of system simplification and aberration free, known as the “lensless holographic projection”. However, the maximum size of optical projected image is limited by the diffraction angle of the spatial light modulator (SLM). In this paper, we present a method for the implementation of image magnification in lensless holographic projection system by using convergence spherical wave illumination to the SLM. The complete complex amplitude of image wavefront is reconstructed in a lensless optical filtering system from phase-only computer-generated hologram (CGH) that is encoded by off-axis double-phase method. The dimension of the magnified image can break the limitation by the maximum diffraction angle of the SLM at a given projection distance. Optical experimental results with successful images magnification in lensless holographic projection system are presented.

       PDF全文 (下载：4)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Zhang Han   Zhang Zhaohui   Zhao Xiaoyan   Zhang Xiaotong   Zhang Tianyao   Cao Can   Yu Yang  

      摘要 + ：(浏览：29次) | 此论文可免费阅读 (可能需要登录)

We present using a specific-window method to subtract the interference of water vapor on terahertz frequency-domain spectroscopy (THz-FDS) at ambient temperature and pressure. A continuous-wave spectrometer based on photomixing was utilized to obtain THz-FDS of methanol vapor in the range of 50~1200 GHz. The distinctly spaced absorption features in the neighborhood of atmospheric windows of transparency were selected to perform linear fitting versus the calculated absorption cross section to obtain the concentration of methanol. Furthermore, the gradually decreased methanol vapor was quantified to demonstrate the reliability of the method.

       PDF全文 (下载：3)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Liu Jingsong   Cheng Qiyuan   Yue Daguang   Zhou Xucong   Meng Qingtian  

      摘要 + ：(浏览：36次) | 此论文可免费阅读 (可能需要登录)

In this paper, we study the molecular alignment and orientation driven by two elliptically polarized laser pulses. It is shown that the field-free molecular alignment can be achieved in a three-dimensional(3D) case while the field-free molecular orientation only along the x and y directions, and that the field-free alignment and orientation along different axes is related to the populations of the rotational states. It is demonstrated that changing the elliptic parameter is efficient for controlling both in-pulse and post-pulse molecular alignment and orientation. And the delay time also has an influence on the field-free molecular alignment and orientation.

       PDF全文 (下载：8)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Shen Xiaojie   Zhou Xian   Huo Jiahao   ZHONG KANG PING   Yuan Jinhui   Tu Jiajing   Long Keping   Yu Changyuan   Lau Alan   Lv Chao  

      摘要 + ：(浏览：25次) | 此论文可免费阅读 (可能需要登录)

Stokes vectors direct detection (SV-DD) is an effective solution for short-reach optical communications. In this paper, we investigate 2D-modulation direct detection systems based on three Stokes vector receivers (SVRs). The influences of three key factors, including the states-of-polarization (SOP), the splitting ratio of the coupler, and the excess loss (EL), are studied in detail. It is shown that the splitting ratio for achieving optimum performance will be changed with SOP and EL conditions. Among these SVRs, the 3 × 3 coupler-based receiver with its optimal splitting ratio shows the best BER performance and stability against the change of SOP.

       PDF全文 (下载：1)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Sun Xiaoyan   Cui Dongmei   Hu Youwang   Chu Dong kai   Chen Guowei   Yu Jinlong   Zhou Jianhang   Duan Ji'an  

      摘要 + ：(浏览：51次) | 此论文可免费阅读 (可能需要登录)

In order to improve the morphology of microchannels fabricated by femtosecond laser ablation, the thermal process was introduced into the post-treatment processing. It was found that thermal process can not only decrease the roughness but also the width and depth of the microchannel. The change rates of width, depth, and roughness of microchannel increases with processing temperature. When we prolong the time of constant temperature, the change rate of width decreases at beginning, and then it tends to be stable. However, the change rates of depth and roughness increase, and then they tend to be stable. In this paper, we discuss the reasons of the above phenomena.

       PDF全文 (下载：1)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Xing Jianfei   Wen Jianxiang   Wang jie   pang fufei   Chen Zhenyi   Liu Yunqi   Wang Tingyun  

      摘要 + ：(浏览：27次) | 此论文可免费阅读 (可能需要登录)

A few-mode erbium doped fiber (FM-EDF) is fabricated using MCVD in combination with liquid solution, and the core and cladding diameters of the fiber are approximately 19.44 and 124.12 μm, respectively. The refractive index difference is 0.98%, numerical aperture (NA) is 0.17, and normalized cut-off frequency V at 1550 nm is 6.81. Therefore, it is a five-mode fiber, and can be used as gain medium of higher order mode. Furthermore, a long period of fiber grating (LPFG) is fabricated, which can convert LP01 mode to LP11 mode, and its conversion efficiency is up to 99%. And the first order orbital angular momentum (OAM) is also generated by combining LPFG and polarization controller (PC). Then, an all-fiber amplification system based on FM-EDF and LPFG, for LP11 mode and first order OAM beams, is built up. Its On-Off gain of LP11 mode beam is 37.2dB at 1521.2 nm. And the variation, which transverse mode field intensity of first order OAM is increased with the increasing of pumping power, is obvious. These show that both LP11 mode and first order OAM beams are amplified in the all-fiber amplification system. This is a novel all-fiber amplification, which can be used in the optical communication fields.

       PDF全文 (下载：2)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Ge Xulei   Yuan Xiaohui   Yuan Fang   Wei Wenqing   Yang Su   Liu Feng   chen min   Zhao Li   Sheng Zhengming   Zhang Jie  

      摘要 + ：(浏览：34次) | 此论文可免费阅读 (可能需要登录)

The temporal profiles of high-power short-pulse lasers reflected from self-induced plasma mirrors (PM) were measured with high temporal resolution in the sub-picosecond window. The leading front shape of the laser pulse is found to depend sensitively on the laser fluence on PM surface. The spectral modulation is found to play a key role in pulse profile shaping. Our finding will extend our knowledge on properly using plasma mirror.

       PDF全文 (下载：4)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Han Zhihang   Sun Cuiting   Jin Xiren   Jiang Hang   Yao Chong   Zhang Shuo   Liu Weiliang   Geng Tao   Peng Feng   Sun weimin   Yuan Libo  

      摘要 + ：(浏览：64次) | 此论文可免费阅读 (可能需要登录)

A torsion sensor based on the near-helical long period fiber grating (NH-LPFG) is fabricated by using a high frequency pulsed CO2 laser. Each groove of the NH-LPFG is spirally written in the four sides of a single mode fiber. The NH-LPFG has a helical periodic vertical index modulation. This is different from the screw-type index modulation of the common H-LPFGs fabricated in a twisted fiber. The torsion and temperature characteristics of the NH-LPFG are experimentally investigated. The temperature sensitivity is about 0.0668 nm/°C. The torsion sensitivity is 0.103 nm/(rad/m) and independent to the polarization state of incident light.

       PDF全文 (下载：16)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Zhang Li   Li Fangye   Wang Shuai   Wang Qi   Luan Kairan   Chen Xi   liu xiuhuan   Qiu Lingying   Chen Zhanguo   Zhao Ji-Hong   Hou Lixin   Gao Yanjun   jia Gang  

      摘要 + ：(浏览：85次) | 此论文可免费阅读 (可能需要登录)

In this paper, we have demonstrated significant electric field induced (EFI) optical rectification (OR) effects existing in the surface layers of germanium (Ge), and measured the distributions of EFI OR signals along the normal directions of surface layers of Ge samples. Based on the experimental results, the ratios of the two effective second-order susceptibility componentsχ_zzz^((2eff))/χ_zxx^((2eff)) for Ge(001) , Ge(110) and Ge(111) surface layers can be estimated to be about 0.92, 0.91, and 1.07, respectively. The results indicated that the EFI OR can be used for analyzing the properties on surface layers of Ge, which has potential applications in Ge photonics and optoelectronics.

       PDF全文 (下载：24)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

zhou linjie   Wang Xinyi   Lu Liangjun   Chen Jianping  

      摘要 + ：(浏览：117次) | 此论文可免费阅读 (可能需要登录)

Optical delay lines (ODLs) are one of the key enabling components in photonic integrated circuits and systems. They are widely used in time-division multiplexing, optical signal synchronization and buffering, microwave signal processing, beam forming and steering etc. The development of integrated photonics pushes forward the miniaturization of ODLs, offering improved performances in terms of stability, tuning speed and power consumption. The integrated ODLs can be implemented using various structures, such as single or coupled resonators, gratings, photonic crystals, multi-paths switchable structures, recirculating loop structures. The delay tuning in ODLs is enabled by either changing the group refractive index of the waveguide or changing the length of the optical path. This paper reviews the recent development of integrated ODLs, with a focus on their abundant applications and flexible implementations. The challenges and potentials of each type of ODLs are pointed out.

       PDF全文 (下载：12)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Liu Jiao   Liu Yang   Tang Xiaojun   Wang Chao  

      摘要 + ：(浏览：73次) | 此论文可免费阅读 (可能需要登录)

We demonstrate a high-efficiency and high-power quasi-three-level laser based on a trapezoidal composite slab architecture with a 270 μm-thick Yb-doping surface. The design of surface-doped slab architecture, temperature effects, laser oscillator model and laser oscillator experiments with surface-doped slab as laser host media have been presented. By theoretical calculation, the temperature rise in the surface-doped slab is only seventh of that is in the bulk doped slab at the same maximum pump power of 30 kW. Finally, in the laser oscillator experiments, the output energy of 21.6 J is obtained when the pump energy is 48 J with the repetition rate of 5 Hz and pulse width of 1 ms. The optical-optical efficiency is 45%.

       PDF全文 (下载：13)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

xu longbo   Liu Shijie   Zhu Ri Hong   Zhou You   chen jie  

      摘要 + ：(浏览：50次) | 此论文可免费阅读 (可能需要登录)

In this paper, a test method based on oblique incidence is practically implemented in the interferometric measurement process. Three sets of wavefront data are achieved through cavity interference measurement with a Fizeau interferometer and one oblique incidence measurement. An iterative algorithm is applied to retrieve the matrix of transmission flatness and reference flatness. The new method can not only calibrate the reference flat error of interferometer, but also provide the absolute measurement method for high precision optical components applied in high power laser systems.

       PDF全文 (下载：7)        Chinese Optics Letters ，2018年第16卷第10期 pp.10      

Zhao Zixin   Zhuang Yiying   Xiao Zhaoxian   Zhang Hangying   Fan Chen   Geng Hehui   Zhao Hong  

      摘要 + ：(浏览：79次) | 此论文可免费阅读 (可能需要登录)

The phase modulation characteristics of a reflective liquid crystal spatial light modulator (LC-SLM) under oblique incidence are studied by using our proposed self-interference method. The experimental setup of the method is very simple and has good robustness to mechanical vibrations. By changing the gray value of the combined grayscale loaded on the LC-SLM, different sheared fringe patterns, generated by the interference between the constant phase-modulated beam and the +1 order diffracted beam of the blazed grating, can be obtained. The amount of phase modulation of the LC-SLM is obtained by subtracting the phase of the two side lobes in frequency domain. By turning the turntable where the SLM is mounted, the phase modulation characteristics at different incident angles can be measured. The experimental results show that the phase modulation curves do not change significantly with the small angle. When the angle is large (i.e. larger than 10 degrees), the phase modulation curves become different especially for the high gray levels. With the increase of the incident angle, phase modulation depth is reduced. The results indicate that the incident angle plays an important role in the performance of the phase modulation of an LC-SLM.

       PDF全文 (下载：13)        Chinese Optics Letters ，2018年第16卷第9期 pp.09