| As a very important branch of applied optics, optical thin film has a drastic advance with the development of spectral interference technology, laser technology, spatial optics, information processing technology and polarizing modulates technology recently.Optical thin film was originated from 19 century. The theory of electromagnetism that Maxwell invented in 1873 was the basis of the entire optical thin film problem. But the optical thin film was really advanced after the vacuum device appeared in 1930,which provide a guarantee to optical thin film. The invention of laser also accelerated the development of optical thin film since 1961. Optical thin film plays very important role in increasing and reducing the refraction, absorbing, transmission, in composing and reducing chromatic color, in modulating the polarizing state and changing phase of light. In short, almost all the optical system uses the character of optical thin film.All the optical character of thin film is based on the interference of light inside. The essence of optical thin film is that the refractive light and transmitted light that come from different surface have interference result in the refraction and transmission direction. Based on the above reason, optical thin film can control the interference thorough changing the material and thickness of thin film. So it can reallocate the intensity of light according to your demand. That is to say to realize certain optical role. Because the optical thin film is normally multiplayer, the interference is very complex. So it can reduce refraction of the surface and increase the transmission, or reduce transmission of the surface and increase the refraction, give high refraction or transmission at certain wavelength; make different polarizing plant and different polarizing character.When modulating the light, isolating light and processing informationof light, it is normal to change nature light into polarizing light. These processes need polarizing device. The normal polarizing device is made of Iceland crystal that is based on birefringence of crystal. Its merit is high extinction ratio, high transmission and wide wavelength. But the normal Iceland crystal is a nature crystal and transparent. It is not easy to find pure and big Iceland crystal, so it is difficult to make large-size polarizing device. At the same time, the process is complex and with high price. Polarizing beam splitter prism (PBS) is based on the interference inside thin film and the law of Brewster. The merit is that it has big aperture, low dissipation and flexible design. Without size limit, with low price and flexible design according to various design and manufacture method, so it is widely used in optical device, laser technology, optical display and optical store.If we suppose 0, n0, nL, HH expressing incident angle, refractive index of glass prism, refractive index of low and high thin film material respectively. The MacNeille PBS must meet the following equation.In this paper, our emphasis is how to optimize the character of this kind prism. Based on the Macneille design and the basic principle optical thin film, we improve the extinction ratio of PBS through changing the structure and interference that can erase the P polarizing refractive both on the front and back side. At the same time, we improve the splitting character of this prism through the optimization of deposition technology. All details are as following.In Charter One, the basic point and essence of this thesis are given.In Charter Two, we represent the history and existing state of thin film the basic character of thin film and the normal calculation method of thin film. The characteristic calculation method and interference of thin film areIn Charter There, we analyze the history and existing state of polarizing beam splitting prism. We deduce the basic Macneille PBS equation, which are the refractive index match term and phase match term. At the same time, we calculate the refraction ratio of P polarizing light and S polariz... |
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