Realization of a Coherent Optical DPSK Heterodyne Transmission System with 565 Mbit/s at 1064 nm

Kurzfassung

We describe the realization of an optical 565 Mbit/s DPSK heterodyne breadboard communication system at 1064 nm for experiments concerning future space applications. The optical transmitter is based on a diode-pumped Nd:YAG single mode TCM laser with 620mW which has been offset-locked to a stble low powerring laser. Phase modulation is obtained by a LiNbO3 travelling wave modulator. The receiver frontend consists of two InGaAs PIN Photodiodes in a balanced configuration and a transimpedance amplifier. The IF of 1130 MHz (only twice the data rate) is stabilized by an AFC which is able to follow frequency deviations of more than 10 GHz. The DPSK encoder and the clock/data recovery unit is based on GaAs technology.The whole system works with a single 12 V power supply useful when performing outdoor experiments. To obtain a bit error rate of 10-10 a received light power of less than -48 dBm is required.