In the practical application of the laser, it is necessary to use the laser beam shaping technology to shape the output beam of laser device to the uniform light intensity distribution. The shaping divergent optical system of compound eye integrator way is composed of beam expanding mirror group and lens array. Its working principle is to expand the output laser to a certain size of caliber, and then divide the beam with lens array into multiple sub beam, where the lens unit of lens array can control the divergence angle of sub beam through the design of focal length, with mutual superposition of the sub beam in far field, to make up for the nonuniformity of beam, so that the radiant exitance on the radiated surface may become uniform. In this paper, we use a reflective microlens array to realize the laser beam shaping. By through of the practical optical path model established, the ray tracing is carried out and the simulation results for single-mode Gaussian beam with noise circumstance is provided. The analysis results show that the laser beam shaping under different inputs can be effectively realized by use of microlens array. All the energy is within the signal window, with a high energy efficiency of more than 90%; The measured surface has a better uniformity, and the uniformity is better than 99.5% at 150m.
Star sensor is a special high accuracy photoelectric instrument. It is often used in navigation of aircraft, cruise missiles,
and ballistic missiles, so the imaging quality of the optical system in a star senor is very important. The spherical
windows with a small impact to imaging performance are usually used in traditional star sensors. However, the spherical
surfaces are not ideal aerodynamic surfaces and would cause problems such as high drag. In this paper the conformal
window whose outer shape is neither spherical nor flat is used in a star sensor. Unfortunately, the conformal shape
introduces amounts of aberration which may lead to low imaging resolution. The various correctors can be used to
eliminate the aberrations, for example, the fixed corrector, the arch, Zernike wedges, and the deformable mirror. The
fixed corrector method is selected to decrease aberrations from the conformal window in this paper. The surface of the
conformal window in the star senor is described as the Von Karman equation. The field of view is 17.6°×13.5°, and the
size of the CCD pixel is 6.45 um×6.45um. The optical design program ZEMAX is used to design this system. After the
optimization, under the max frequency of 77.52lp/mm, the MFT can almost achieve 30%. The design results show that
the aerodynamic requirements can be satisfied by the application of the conformal window in the star sensor, and the
aberrations can be corrected by proper ways.
The wavefront error and polarization of a side mounted infrared window made of ZnS are studied. The Infrared
windows suffer from temperature gradient and stress during their launch process. Generally, the gradient in temperature
changes the refractive index of the material whereas stress produces deformation and birefringence. In this paper, a
thermal finite element analysis (FEA) of an IR window is presented. For this purpose, we employed an FEA program
Ansys to obtain the time-varying temperature field. The deformation and stress of the window are derived from a
structural FEA with the aerodynamic force and the temperature field previously obtained as being the loads. The
deformation, temperature field, stress field, ray tracing and Jones Calculus are used to calculate the wavefront error and
the change of polarization state.
A great deal segmented mirror errors consisting of piston and tip-tilt exist when space large aperture segmented optics
system deploys. These errors will result in the departure of segmented mirrors images from the view. For that, proper
scanning function should be adopted to control actuators rotating the segmented mirror, so that the images of segmented
mirror can be put into the view and placed in the ideal position. The key of capturing segmented mirror images is
selecting an optimal scanning function. This paper put forward the optimal scanning function principle based on
capturing images by the fastest velocity. The scanning functions, such as screw-type, rose-type, and helianthus-type and
so on, have their own merits and demerits. In my paper, the scanning functions above will be analyzed and discussed. As
a sample, a simulation experiment is carried to study the effects of different scanning functions on three mirror
astigmatism system, whose primary mirror with six segmented mirror. In simulation experiment, the piston and tip-tilt
errors scale and the ideal position of segmented mirror are given, three scanning functions above are used to realize the
capture process by utilizing the improved optics design software ZEMAX, the relationship between scanning functions
and optical system are analyzed and the optimal one is determined.
A novel type of adaptive optical system based on direct optimization of system performance metric is studied. The
optimization method is based on stochastic parallel gradient descent (SPGD) algorithm. Theoretical analysis, computer
simulations, and experimental results under point source and extended source conditions are presented.
A Very High Resolution Telescope (VHRT) is designed as a space-to-earth remote sensor and the polarization effect in this VHRT is analyzed in this paper. First, the theory of polarization effect is reviewed. Second, the Jones arithmetic of polarization aberrations in VHRT is presented. Then, CODE V software is used to realize the polarization ray trace in this system and the results of the polarization effect analysis are obtained. The output information includes the plot of Modulation Transfer Function (MTF), the plot of Point Spread Function (PSF), pupil map, relative illumination, illumination, distortion and Strehl ratio. Finally, effective methods to control the polarization effect in an optical system are given. According to the results of analysis, we have drawn the following conclusions. Polarization effect in an optical system shouldn't be ignored to improve the imaging quality; with the incident angle as small as possible to control the polarization effect. Coating design must be considered carefully for the optical design.
The optical system of an infrared multi-spectrum scanner used on the resource satellite is presented in this paper. The principles of spectrum-dividing and imaging, the designing of optical system, the optimization of the assemblage and the adjusting of relay optical system are discussed. According to the general principles of infrared systems, R-C system is used in designing of the primary optical system. There are two methods to design the relay optical system, one of which consists of a complex prism and the other uses a binary optical element. The results and imaging quality of the two methods generated by ZEMAX are given. In the system using complex prism, each wavelength band consists of an R-C system. The diffractive system uses diffractive-refractive hybrid systems to divide spectrum, image and achromatize. The results show that the image quality of the designed system is good enough to meet the practical requirements.