High bit-rate laser communications have been increasingly studied for applications ranging from short-distance transmissions to inter-spacecraft links. Optical communications involving moving parties require precise beam pointing and mutual tracking of communicating transceivers. Current approaches based on electro-mechanical beam steering are limited by the need for large volumes of beam-addressing computing and difficulties in providing automatic tracking/pointing capabilities to compensate for rapid changes in directivity patterns, transmitters’ relative misplacement and jitter [1]. An all-optical adaptive beam-tracking approach, proposed by some of the authors earlier, is based on the double phase conjugation effect (DPC) [2]. No mechanical steering, positioning or addressing computing are needed for fine tracking in such a bi-directional optical link. The approach efficiency strongly depends on non-linear properties of the used optical materials, which have been thoroughly studied [3]. This paper presents the results of theoretical analysis and further experimental studies of the DPC all-optical tracking technology. In the experiment, two optical terminals were linked with a modulated laser signal at a telecommunication wavelength. A DPC-mirror was a multi-layer liquid-crystal stack with a giant optical nonlinearity. The tracking and communication capabilities were simultaneously demonstrated in a range of angles, transmission rates and laser power levels. The experiment was in good agreement with the theoretical model. REFERENCES 1. E Lerner, Laser Focus World 36 11 2000 2. A Dudelzak, A Kuzhelev, A Novikov, G Pasmanik, Patent Application 12346-US-Prov 2002 3. A Kuzhelev, A Dudelzak, J Opt A: Pure and App Opt 5 L5 2003

Date Published: 20 December 2004
PDF: 12 pages
Proc. SPIE 5577, Photonics North 2004: Optical Components and Devices, (20 December 2004);

Published in SPIE Proceedings Vol. 5577:
Photonics North 2004: Optical Components and Devices
John C. Armitage; Simon Fafard; Roger A. Lessard; George A. Lampropoulos, Editor(s)