Abstract

Brewster’s angle thin film polarizing beamsplitters utilize the polarizing region on the long wavelength side of a long wave pass stack of layers. The bandwidth over which effective polarization splitting of the incident light occurs is limited by the ratio of the refractive indices of the coating materials. (A higher ratio gives a broader bandwidth.) For certain applications, the bandwidth must be broad enough to accommodate multiple spectral lines. Immersed designs will accomplish such spectral broadening. However, they are not suitable for high energy laser applications due to low laser damage thresholds of optical cements. The air-spaced cube polarizer, while nominally an immersed design, does not exhibit such bandwidth broadening. A straightforward method for broadening the polarization band of a Brewster’s angle slab polarizer is to combine two separately-centered polarizers into one design.

© 1992 Optical Society of America