Spectral Type White Light Interferometry Ranging And Optical Thin Film Phase Test

In recent years, with the development of femtosecond laser and high speed optic- fiber communication, the study on thin film phase properties has attracted more and more attentions and has become a hotspot in the area of optical thin film. So the characteration methods, used to measure the phase properties of optical thin film, are also important in order to test if the specifications of the manufactured samples agree well with the design. The traditional methods for measuring the optical or non-optical properties of thin film are unable to meet the requirement for the phase characteration. In this thesis, a new technology for the measurement of thin film phase characteristic is proposed by using the spectral white-light interferometric. By this technology, the absolute phase properties of thin film in a wide spectral range could be retrieved in one time. The main contesnts in this thesis are arranged as following:1. The application of spectral white-light interferemetry system in the realm of optical elements dispersive measurements and absolute distance measurements. The key optical element in interferometer and certain optical system, which called beam-splitter is unable to solve the problem of uneven thickness, which leads to the difference of optical path length(OPD). So this essay studied the dispersive of the beam-splitter firstly. The absolute distance of two mirrors was achieved when measuring the effective thickness of the beam-splitter. According to the measurement result on the spectral whit-light Michelson interferometer, the veracity and reliability of this measurement method was proved by experiment.2. The application of spectral white-light interfrometric system in the measurement of thin film phase characteristic. Firstly, we analyzed the phase characteristic of optical thin film theoretically. Secondly, analysis of the feasibility of this measurement system was made, and a series of involved arithmetic was demonstrated as well as a lot of thin film samples were measured by this system The results show all kinds thin films with different thickness, the system is able to get exact results.At the end of this thesis, the developments to improve this system in the future are given. By using the step motor to promote the micropositioner and using software to estimate the position where the interferogram appears automatically, the automatic measurement system can be realized.This thesis proposed a new way to measure the thin film phase characteristic and also made some contribution to the utilization and industrialization of the real time on line measurement system of thin film phase characteristic.