Abstract

This paper describes an approach in which the wavelength of a semiconductor laser in an optical WDM communication system is sta­bilized and selected with a HOE. We have analyzed planar and curved as well as reflective and transmissive HOE. The optimum system results can be obtained by optimizing parameters. As an example, the design of a very compact HOE system is illustrated. Because of the lack of ideal IR recording materials, the HOE can be generated by a computer and fabricated by known techniques, such as by using an e-beam machine. We also illustrate an alternative CGH technique. First, a CGH with a prescribed phase distortion for the intended IR HOE is fabricated for a visible wavelength. The desired IR HOE can then be exposed with the visible light by using the pre-distorted CGH. Designs of HOE to be used for wavelengths of 780 nm, 830 nm, 1300 nm, and 1500 nm will be shown. The switchable wavelength spacing is 1 nm with an accuracy of better than 0.1 nm and switchable range is 35 nm. Computer simulations and experimental results will be shown.

© 1992 Optical Society of America