BPSK homodyne and DPSK heterodyne receivers for free-space communication with ND:host lasers

摘要

An investigation of the most promising coherent receiver configurations for application in Nd:YAG laser based optical transmission links is presented. A BPSK homodyne receiver based on a Costas phase locked loop was realized for a data rate of 600 Mbit/s, using a commercially available diode pumped ring laser at 1064 nm. Furthermore a DPSK heterodyne receiver with the same data rate using an intermediate frequency of 1.2 GHz was realized. Both have been tested successfully. An optical 90 degrees-hybrid, built of bulk optical components was used for the investigation of the receivers. Design and performance of this bulk hybrid are described.