The Optical Film In The Projection Display Applications, And Optical Switches

Since 1990s, the rapid development of projector display and optical communications promotes optical thin film's progress, and more technology requests appear in the optical coating field. In response to the demands of liquid crystal (LC) projector and LC optical switch, optical thin films correlated are designed and discussed. The research work in this paper is as follows.LC optical switch designed in this paper is based on optical modulation that the electric field can change the direction of optical axis of liquid crystal, resulted in the variance of refractive index. It can achieve high cutoff and great extinction coefficient.The indium-tin-oxide (ITO) thin films are discussed. Using Drude model, the refractive index of ITO thin films is estimated with the measured transmittance. The optical performance (n, k) differences between ITO thin films developed by magnetron sputtering and those by e-beam evaporation are compared. An ITO structure is produced with the average transmittance 95.9% from 1.1 jxm to 1.7|om. Another ITO structure is designed with the reflectance lower than 0.2% in C band of optical communications.The design of broadband and wide angle Polarizing Beam Splitter (PBS) is optimized with the primary structure of several film stacks. The broadband and wide angle PBS was manufactured and its transmittance extinction coefficient achieved 700:1.Long wavelength pass and short wavelength pass thin film structures are designed and produced. Changing the low refractive index material, the separation of s- and p-polarized light reduces from 7nm to 4nm. Applying the anti-polarization structure, the separation decreases to about 2.3nm.In response to the special requires of the antireflection coatings on Plexiglas, a practical coating with stable color and high production yield is investigated.