A modified iterative algorithm based on phase mixture was put forward in designing diffractive optical elements, aiming at recovering diffractive patterns of the output beam precisely. Different from Gerchberg-Saxton algorithm, in this paper, the new phase initiation was set as the weighted sum of the two phase functions in the succeeding neighbor loops to be immune from trapping local minimum. The formulas for calculating phase factor were given, and the selection of phase factor was discussed. The beam transformations from Gaussian distribution to uniform and to annular distribution were exampled to investigate with Gerchberg-Saxton algorithm and the proposed algorithm. The numerical result demonstrates a nearly uniform and annular target profile, and the ultimate mean square error, top beam uniformity, and energy efficiency of the proposed algorithm were all more excellent than Gerchberg-Saxton algorithm. This work can obtain better output diffraction pattern, and has reference value for the design of diffractive optical elements.

Jianjie Yu;晶 马;Liying Tan;Qiqi Han

Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering

2013-9

The design of a phase-only diffractive WDM element, based on vector theory, is demonstrated. The adopted method of this design is a rigorous method based on the rigorous electromagnetic computation models the Beam propagation method (BPM)., Rayleigth-Sommerfield diffraction theory, and iterative optimization method. This phase-only diffractive optical WDM element (PDOE-WDM) is motivated by the intersatellite optical communication (IOC). And the motivation also raises the demands of large numerical aperture, polarization insensitivity and high diffraction efficiency. In order to predict the phase filter of DOE and the large angle diffraction precisely, a vigorous vector method has been adopted. The complex optical field right behind the BOE is computed by the Beam propagation method (BPM). And the diffraction between the back side of DOE and focusing plane is computed by the means of Rayleigth-Sommerfield (RS) diffraction theory, a more rigorous diffraction theory than Fresnel diffraction theory. The vector BPM method and the RS diffraction theory combined with FFT technology come along with the improvement of PDOE-WDM performances. And the high performance PDOE-WDM will play an important rule in IOC to increase communication rate as well as decrease volume and weight.

Yun Liang Chen;晶 马;Li Ying Tan;Qi Wang

Proceedings of SPIE - The International Society for Optical Engineering

2005

Based on a truncated ellipse Gaussian model for localized distortion in transmission-type optical antenna, the receiver power penalty due to localized wavefront deformation is researched. It is shown that the receiver power depends on distortion deepness h, radii a and b, and position d, and changes regularly with them. Localized distortion has the greatest influence on receiver power at a depth of h≈1.45λ, which does not depend on other deformation parameters. The maxima of the receiver power penalty for different distortion radii are given. To reduce the impact of localized distortion on the receiver power, the machining precision of lenses should be better than 1.45λ. We hope the results can be used in the design of intersatellite laser communication systems.

Liying Tan;Yuqiang Yang;晶 马;Jianjie Yu

Optical Engineering

2009

Highly precise pointing is needed in satellite optical communication systems because of the extremely narrow laser beam. The axis error angles can cause large pointing error angles. In this paper, the matrixes of the axis error angles were given through geometric optics. And the models of pointing error angles caused by the axis error angles were built in the periscope-type optical communication terminals. The models show that the pointing error angle of azimuth axis increases quickly when the elevation angle θ _EL is approximate to 0° or 180°. The correction of axis error has been performed and the pointing error angles have been corrected. This work provides the theory that can benefit the design and assembling of periscope-type optical communication terminals, and it can amend the pointing error angles caused by axis error angles during working. Besides, according to these models, some optical elements, whose position errors cause pointing error angles, can be researched by quantitative analysis.

Shichen Wu;Liying Tan;Siyuan Yu;晶 马

Optics and Laser Technology

2013-3

Satellite laser communication has become a hot topic of communication technology research, and the optimal design of the optical system is an important research direction of the satellite laser communication terminal. Diffractive optical elements were introduced in this paper, to realize the miniaturization, integration, high efficiency of satellite laser communication terminals. Followed by the brief introduction of the principle of laser communication system, the potential applications of diffractive elements within a laser terminal were exhibited, such as beam shaping and splitting, optical filtering, antireflective coating, aberration and thermal compensation, etc. A design example of laser terminal including diffractive elements was presented, and the consequential simulation results demonstrate the advantage compared with conventional refractive elements.

Jianjie Yu;Qiqi Han;晶 马;Liying Tan

Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering

2013-1

The acquistion with antenna scanning in intersatellite laser links was studied both in theory and with simulation. A theorized model for acquisition was given, and some parameters that influence the system of acquisition were analyzed. In order to verify the analytical outcomes, a simulation system for the acquisition in the laboratory was built. The results from the tests accord well with those from the theoretical analysis.

Si Yuan Yu;晶 马;Li Ying Tan;Hui De Gao;祖光 马

Zhongguo Jiguang/Chinese Journal of Lasers

2002-6

CMOS is a good candidate tracking detector for satellite optical communications systems with outstanding feature of sub-window for the development of APS (Active Pixel Sensor) technology. For inter-satellite optical communications it is critical to estimate the direction of incident laser beam precisely by measuring the centroid position of incident beam spot. The presence of detector noise results in measurement error, which degrades the tracking performance of systems. In this research, the measurement error of CMOS is derived taking consideration of detector noise. It is shown that the measurement error depends on pixel noise, size of the tracking sub-window (pixels number), intensity of incident laser beam, relative size of beam spot. The influences of these factors are analyzed by numerical simulation. We hope the results obtained in this research will be helpful in the design of CMOS detector satellite optical communications systems.

Xin Li;Shihong Zhou;晶 马;Liying Tan;Tao Shen

2013

In order to evaluate the performances of the intersatellite optical communication (IOC), the beam vibration, transmitting loss and thermal noise should be analyzed. With the uniform analysis of beam spreading, random vibration, avalanche noise and thermal noise, the formula of sensitivity is given. And the laser transmitting factor (LTF) is introduced to describe the beam spreading and vibration. Utilizing the result, the effects of Gaussian beam on IOC are analyzed, and the means of the decision of system parameters are presented.

Yun Liang Chen;晶 马;Li Ying Tan;Qi Wang

Zhongguo Jiguang/Chinese Journal of Lasers

2004-3

Massive data traffic demand leads to the proposal of satellite constellation networks providing broadband communications for users. The key technology to satisfy the high capacity requirement of future communications between satellites is the optical intersatellite link (ISL). Wavelength-routed optical transport networks over nongeosychronous satellite constellations (WROTNS) show the most promising future, since the networking by means of wavelength division multiplexing (WDM) ISLs with wavelength routing can not only efficiently utilize the optical amplifier bandwidth on board the satellite but also simplify routing decisions and minimize processing delays on board. In the paper we consider that the physical ISL topologies of the WROTNS are the arbitrarily connected networks. Based on the first satellite constellation with the proposal to include WDM ISLs and wavelength routing, its time-variant optical ISL topology is analyzed, and then a large number of randomly generated connected networks with distinct topologies are investigated to estimate the bounds of wavelength requirements. The results show that wavelength requirements of the WROTNS are determined by percentage of active terminals, maximum admissible ISLs hops, and the number of optical ISL terminals on board, and they are also time dependent. The topologically regular WROTNS are studied as well. These works are helpful to evaluate the design of constellation networking.

Liying Tan;Qinglong Yang;晶 马;Shiqi Jiang

Journal of Optical Communications and Networking

2010-4

The generally Galileo optical experiment is analysied, included the analysis to components used in the experiment. The paper is focused on the analysis to the operational principle and working course of laser transmitter, and the working concept of PAT subsystem (pointing, acquisition, and tracking). The experimental result is analyzed detailedly. Contrapose to the failed receiving from the effect of atmosphere and weather, the feasibility of the scheme that adaptive optics techniques to mitigate the atmosphere-induced signal fades is discussed. At the same time, to the problem that background light resulting in the performance of link worse, the feasibility of the scheme is discussed that interferential light, filler to restrict background light and provided the referenced opinion to the research of deep space optical communication of China.

Ke Hua Xu;晶 马;Li Ying Tan

Yuhang Xuebao/Journal of Astronautics

2006-4