Binary optical lens is featured not only smaller physical volume, lighter weight and e easy replication on application, but
also high diffractive efficiency, special chromatic dispersion function, more design freedom and more material. Thus in
this paper, the authors mainly analysis and calculate the properties of monochrome elementary aberration, and improve
the optical design of telescope system by using refractive-diffractive lens. This result showed that this new approach
could be performed.
Visibility is an important meteorological observation factor. It shows vital position of shopping, environments monitoring and military zones. The design of optical probe for forward scattering visibility meter belongs to normal energy transmitting system. It needs that there are fewer lenses to be used to prevent energy dissipation. Because there is pollution to the monitoring and heating device, the aspheric system is adopted. The basic performance parameters are calculated according to technical data. And the aberration spectrum and tolerance are determined. Based on above parameters, the structure type of objective, which is combined by aspheric and plano surface, is determined. It is showed from the calculation result that all kinds of aberrations of aspheric objective lens could meet the demand of the system.
By using Radio Frequency and Plasma Enhanced Chemical Vapor Deposition(RF-PECVD), GaP film is fabricated on ZnS substrate. Under low load condition, the film features Vickers hardness of 750kgf/mm2and film thickness of 10μm. With designed and fabricated DLC/GaP/ZnS film system on ZnS substrate with thickness of 4.2mm, the average transmittance in the bandwidth 8~12μm reached 80.4%. It is indicated by the study of deposition rate of GaP film, optical and mechanical properties and anti-rain erosion and anti-sand erosion that the film growing rate will be faster with the increase of RF power and the deposition rate will be decreased because of the increase of substrate temperature, so it is as the lab atmospheric pressure increase. However , it has more defects in films with the increase of RF power and this results in more absorption, reflection and scattering in the IR transmittance. The higher lab atmospheric pressure and vacuum is, the less impurity in the deposited film will be. GaP film has the ability of protecting ZnS substrate from rain erosion and this ability increases by the thickness of film. And the combination of DLC and GaP has excellent property in anti-sand erosion.
Photoresist spherical microlens array pattern can be fabricated by using multiple mask photoengraving and thermofusion forming process. By reactive ion beam etching, the spherical photoresist microlens array can be transferred effectively to a quartz substrate. The experimental parameters of the fused quartz microlens are the mean curvature of 40μm, mean bottom size of Φ56μm, mean apex height of 10.6μm.Scanning electron microscope (SEM) and surface contourgraph show that the pattern of spherical microlens array prepared is regular and well distributed, the configuration of each
fused quartz microlens is clear. Its surface is smooth and sleek. Experimental results show that by controlling amount of exposure according to spatial distribution, any surface structure which meets demands can be fabricated on photoresist of a certain thickness. In the process of microlens array pattern transfer by using reactive ion beam etching, etching parameters can be adjusted independently and controlled accurately. In the process, various technical processes can be schemed according to various demands, the best etching technique can be selected. In this paper, main process of microlens array fabrication is narrated. Main factors with influence on fabrication are analyzed.
Inhomogeneous GexC1-xfilm has been prepared by making use of reactive radio frequency magnetron sputtering method. In 8 ~ 12 μm waveband, average transmission rate after film sedimentation on CVD/ZnS single surface is 79.1%, larger than that before filming at 7.8%. As a result of experiments, when ratio of reaction gas flow rate CH4/Ar+CH4changes, refraction ratio of GexC1-x film varies in range of 2.4 ~ 4.1 according to the difference of component X. It makes design of multilayer films and preparation of wide waveband inhomogeneous films very easy. Factors influence transmission rate of GexC1-x film, relationship between refraction ratio of film and ratio of reaction gas flow rate, relationship between film sedimentation speed that corresponds to different refraction ratio and ratio of reaction gas flow rate are analyzed and discussed in this paper.
Based on reactive ion etching (RIE) technology, a 2-D symmetric tetragonal and columnar subwavelength surface relief structure for infrared antireflection can be made on silicon wafer. By analyzing the impact on etch rate, anisotropy and uniformity caused by some technological parameters in reactive ion etching (RIE), parameters such as etchant gas, concentration and flow rate of the gas, pressure of reaction room and radio-frequency power density can be selected. Meanwhile, surface structure appearance, parameters and infrared transmission performance of etching sample have been measured, and the measure results have been analyzed according to technological demands.