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Gao L.,Harbin Institute of Technology | Wang C.,Harbin Institute of Technology | Ji Y.,Tianjin Key Laboratory of Optical Thin Film | Li Y.,Harbin Institute of Technology | And 2 more authors.
Optical Review | Year: 2010

All-fiber digital heterodyne interferometry is a laser metrology technique employing pseudo-random codes phase modulated onto an optical carrier signal. In this heterodyne interferometer system, the optical signal includes signal reflected and transmitted from the sample, respectively. Compared with the conventional heterodyne interferometry, this enhanced optical system has much higher measurement sensitivity, and can distinguish the signal which reflected from the front and the rear surface of the sample. Analysis and simulation for the digital heterodyne interferometry are presented. It takes approximately 4 s to scan the whole surface with the diameter of 300 mm. The thickness profile of the sample is obtained in the experiment. The discussion about the experiment is given finally. © 2010 The Optical Society of Japan.


Ji Y.,Harbin Institute of Technology | Ji Y.,Tianjin Key Laboratory of Optical Thin Film | Liu H.,Tianjin Key Laboratory of Optical Thin Film | Wang Z.,Tongji University | And 7 more authors.
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2011

With the development of laser technology, there is a requirement of the antireflection coating with ultra-high transmittance. It is crucial to consider the influence of the surface characteristics of substrates during the design, manufacture of high precision antireflection coating. In this paper, the substrate was fused silica and Ta2O5 and SiO2 were selected as high index and low index materials respectively. The 532 nm laser antireflection coating at normal incidence was designed, and the electric field distribution was calculated, while the surface roughness was considered as a mixed layer of geometric proportion volume. Then, the ideal V-type antireflection coating with interface layers of different thickness was calculated, and the numerical function relationship between the transmittance and the interface roughness was founded. At last the ideal design was optimized by numerical method, and the thin film structures with interface layer were gained. Research result is helpful to designing and preparing for the antireflection coating at short wavelength with ultra high transmittance.


Liu H.,Tongji University | Liu H.,Tianjin Key Laboratory of Optical Thin Film | Liu D.,Tianjin Key Laboratory of Optical Thin Film | Ji Y.,Tianjin Key Laboratory of Optical Thin Film | And 9 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

The optical characteristics of substrates are the essential content of research work for thin film optics. The spectrophotometer is one of the important instruments to test transmittance and reflectance of different substrates or coating components. The test accuracy of transmission spectrum of the substrates has direct influenced on optical constants reverse engineering of thin film on the substrate. In this paper, SCHOTT grade LITHOSIL-Q0 fused silica substrate was chosen as standard substrate and was tested transmission spectrum in region 380nm-860nm to use the Lambda-900 spectrophotometer. By comparing the measured transmission spectrum with standard SCHOTT grade LITHOSIL-Q0 fused silica substrate transmission spectrum can be calculated measured errors. In the experiments, the orthogonal experimental design method is used. Sample pool aperture, scan speed, slit width and sampling data interval operating parameters were chosen as key factors (three levels were chosen in each factor). L9 (34) orthogonal table was used for analysis the experiments results. Nine experiment results analyzed to determine the operating parameters of the influence measured accuracy were as follows: the sample pool aperture, scan speed, slit width, the sampling data interval. Finally, no iris, scan speed 250nm/s, slit width 3nm, sampling data interval 1nm were used a combination of the operating parameters to measure of transmission spectrum of the SCHOTT grade LITHOSIL-Q0 samples. Measured maximum and minimum absolute error are 0.1355% and 0.0771%, respectively. The operating parameters could be applied to transmittance spectrum test of every substrate, or the spectrum could be extended. © 2010 Copyright SPIE - The International Society for Optical Engineering.


Dun X.,Tianjin Jinhang Institute of Technical Physics | Dun X.,Tianjin Key Laboratory of Optical Thin Film | Tao Y.,Tianjin Jinhang Institute of Technical Physics | Tao Y.,Tianjin Key Laboratory of Optical Thin Film | And 2 more authors.
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2010

The formula of calculating narcissus level was introduced, which included three parts: standard equivalent temperature difference (SETD), optical efficiency ratio (OER) and narcissus coefficient (NIC). Narcissus suppression methods were discussed based on these three parts, and then a project of narcissus suppression in the scanned imaging systems was proposed. On the premise of the imaging quality of optical systems only a slightly decreasing, the OER was selected appropriately, the NIC was reduced as much as possible, the refraction surface which could not be controlled by the NIC was deleted directly, and then aspherical surface or diffraction surface were used as required. The traditional optical design suppression method did not work well in reducing the NIC, thus a new method of direct control the height of rays on cold aperture was introduced, which was applied successfully in the narcissus control in the dual-FOV IR scanned imaging systems. Compared with the traditional methods, the new method has the advantages of direct and high degrees of freedom in optimization.


Jiao L.,Tianjin Jinhang Institute of Technical Physics | Jiao L.,Tianjin Key Laboratory of Optical Thin Film | Tong Y.,Tianjin Jinhang Institute of Technical Physics | Tong Y.,Tianjin Key Laboratory of Optical Thin Film | And 6 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

Along with the higher demand of super smooth optical surface, the cleaning technique that is the critical process to obtain super smooth surface has to meet even higher standards. In virtue of higher efficiency and better effect, the ultrasonic cleaning technology has been widely used in cleaning high-end optical lenses. This paper introduced the process, principle and method of the ultrasonic cleaning technology for a super smooth surface. The basis of determining the main technical parameters, such as the power and frequency of ultrasonic wave, the ultrasonic time, the components of cleaning agent and its operating temperature, were also discussed. In addition, the progress situations of ultrasonic cleaning technologies including the characteristics of complex frequency ultrasonic and megasonics cleaning technology and the removal mechanism of different granularity of dirt were analyzed. The mechanism of complex frequency ultrasound produces chemical process and the relationship between megasonics boundary layer and the particles removing were studied. Results showed that the chemical functions of complex frequency ultrasound and megasonics were better than that of single frequency ultrasound for the particles removal effect. Therefore, the new complex frequency ultrasonic and megasonic cleaning technologies are very necessary for cleaning optical components. © 2014 SPIE.

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