Optical Cyclic Wavelength Shifter Using a Dual-Band Polymer Holographic Grating

Abstract

We propose a cyclic wavelength shifter, that can be applied to optical networks or code-division multiple access (CDMA) systems. The shifter is based on a dual-band polymer holographic grating and operated by applying strain or rotation. Using this device, constant-weight cyclically permutable codes in various CDMA systems might be implemented easily compared with using other optical methods.

A simply tunable optical CDMA encoder/decoder for two-dimensional cyclic permutable codes

“…In this letter, we propose and demonstrate a simply tunable optical codec for time-spreading/wavelength-hopping 2-D codes using cyclic wavelength shifter. Our device is composed of a dual-band holographic grating (DHG), fiber array, and fiber delay lines corresponding to assigned wavelengths, and other coupling optics [7,8]. We confirmed that our device was capable of flexible encoding/decoding operation and easy tuning.…”

“…is collimated and impinges on the DHG fixed on a rotation stage. Each diffracted wave is focused on different locations at the focal plane of the out-coupling lens and the focused outputcoupling positions are shifted by rotating or applying strain to DHG [8]. At first, the output wavelength components X -3 are coupled to predetermined fibers entitled # (1) -(3), respectively.…”