Aiming at the complex structure, difficult installation and high cost of the multispectral camera optical system used for phenological observation, a miniaturized and snapshot multispectral camera scheme is proposed. A compact and multi-channel image parallel optical system is designed by using a four-sided pyramid prism as an important optical element. The field-of-view of the system is ±3°, the working band is 400nm-600nm, the focal length is 50mm, and the F number is 5. The design results show that the single wavelength modulation transfer functions (MTF) at Nyquist frequency is better than 0.5, the root mean square radius (RMS) of all field of view is less than 7.4μm, and the distortion is less than 0.5%, which can meet the design requirements of multispectral cameras.
Laser communication has many outstanding advantages, such as high optical gain, high anti-interception, high anti-interference ability and high communication rate, it is an important technical method to solve the problem of high speed communication. The optical antenna is responsible for the reception and transmission of the signal, which is an important part of the laser communication terminal. Based on the general research situation at home and abroad, from the aspect of system SNR and efficiency, this article has determined some targets such as receiving / emission efficiency, wave aberration and ability of off-axis stray light suppression; combined with specific application requirements, we have determined the basic parameters such as communication wavelength: 1545nm, aperture: 100mm, FOV: 0.1 degrees, optical magnification: 15 times. According to the above parameters, a set of reasonable optical antenna system has been designed and the test equipment is set up to measure, the test results are all satisfied. This paper has some reference value for the design and test of laser communication optical antenna.
According to the characteristics of the reflective optical microscope lighting system, an improved Köhler illumination system for the full-field optical coherence tomography system (FFOCT) was designed to realize the illumination of biological samples and living biological tissues. The illumination system differs from the conventional Köhler illumination system. The filament of the halogen lamp is imaged on the back focal plane of the microscope objective, then parallel light is incident on the sample plane. The improved Köhler illumination system uses a halogen lamp as the light source and is divided into two parts: the condenser front and rear groups. The front condenser group uses two double-glued structures, and the rear group uses a double-coupled lens. The optical design software Zemax was used to optimize the design, and the illumination analysis software Tracepro was used to trace the ray and simulate the imaging of the light source in the front focal plane of the microscope objective. The entire improved Köhler illumination optical path has a total length of 594 mm, the diaphragm is 122 mm from the front group of the condenser, 99 mm from the rear group, and the working distance is 292 mm; the luminous efficiency of the receiving surface is as high as 60.38%, and the edge of the light spot is smooth and clear. The illumination system makes full use of the optical power emitted by the light source and facilitates the placement of a device such as a splitting prism between the condenser and the microscope objective, which satisfies the requirement of the entire machine well.
In order to reduce the optical intensity of backscattering lights of the Cassegrainian optical antenna in the optical system of the laser communication terminal and improve the optical isolation of laser communication system, this paper proposes a method for designing high isolation level Cassegrainian optical antenna by increasing the characteristic value of the optical intensity of backscattering lights E/N. The method aims to improve the optical antenna isolation through reducing the optical intensity of backscattering lights along the incident optical path based on analyzing the theoretical model of the optical intensity of backscattering lights BRDF. A Cassegrainian optical antenna for laser communication is designed in this paper, and the method is used to optimize the isolation of this optical antenna by custom operands in ZEMAX. Then using TracePro software builds the optical structure model of this optical antenna before and after optimization, simulate the optical intensity of backscattering lights of each model, calculate and analyze the isolation of each model by using simulation data respectively. It is show that the backscattering rate of the system decreases from 0.0011956 to 0.00007515, and the isolation decreases from -29.224dB to -41.24dB. Optimization has improved the isolation 12.017dB of the optical system through use the method.
Full-disc vector magnetograph (FMG) is one of the main loads in the Advanced Space-based Solar Observatory. FMG is used to realize scientific goals of observing full-disk vector magnetic field with center wavelength of 532.4 nm. The optical system of FMG consists of polarized optical system and imaging optical system, and the imaging optical system composes of the front window and telescope system. The front window has the capability for providing proper situation for scientific observation by absorbing high energy of solar irradiance coming from space while reflecting wavelength of non-scientific investigation beyond wavelength of 532.4±5 nm. The study analyzed the influence of complex space environment on optical glasses. As a result, the material of fused silica, while two pieces of flat glass parallel with 3mm separation structure and thickness of 15mm are determined. Finally, the results show that design for the front window meet the required specifications.
Due to its advantageous imaging characteristic and banding flexibility, imaging fiber bundle can be used for line-plane-switching push-broom infrared imaging. How to precisely couple the fiber bundle in the optics system is the key to get excellent image for transmission. After introducing the basic system composition and structural characteristics of the infrared systems coupled with imaging fiber bundle, this article analysis the coupling efficiency and the design requirements of its relay lenses with the angle of the numerical aperture selecting in the system and cold stop matching of the refrigerant infrared detector. For an actual need, one relay coupling system has been designed with the magnification is -0.6, field of objective height is 4mm, objective numerical aperture is 0.15, which has excellent image quality and enough coupling efficiency. In the end, the push broom imaging experiment is carried out. The results show that the design meets the requirements of light energy efficiency and image quality. This design has a certain reference value for the design of the infrared fiber optical system.