Crosstalk in a lossy directional coupler switch

Date

1995-07-06

Department

Program

Citation of Original Publication

Chinni, V.R., T.C. Huang, P.-K.A. Wai, C.R. Menyuk, and G.J. Simonis. “Crosstalk in a Lossy Directional Coupler Switch.” Journal of Lightwave Technology 13, no. 7 (July 1995): 1530–35. https://doi.org/10.1109/50.400714.

Rights

This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
Public Domain

Abstract

Crosstalk due to material absorption in a two-waveguide, symmetric directional coupler switch is investigated. In a material with absorption, it is not possible to completely eliminate the crosstalk by adjusting the coupling length. The coupling length for minimum crosstalk differs from that of lossless systems. Theoretical limits of the lowest achievable crosstalk and the corresponding coupling lengths are calculated. The results show that the effect of absorption on crosstalk is more severe when the devices are designed for low crosstalk. The increase in crosstalk due to absorption can be as high as 20 dB. The material absorption is thus a critical parameter in designing low crosstalk devices.<>