A coherent fiber-array-based laser link for atmospheric aberration mitigation and power scaling
Abstract
We report a laser link that can correct atmospheric aberrations. We use a fiber collimator array, fed by a master oscillator with multiple fiber amplifiers (MOMA), and accomplish phase adjustment via pump diode current control. Each of seven channels is tagged by a different 1-20 kHz diode current dither. At the receiver, each channel's phase information is extracted from the <50 kHz signal. Our measurements show 5 kHz phase adjustment capability, so even turbulence-induced aberrations, as well as typical atmospheric aberrations (< 200 Hz) can be corrected. Only in >~100 km-range scenarios is the correction bandwidth limited by light's travel time. The low dither frequencies and amplitudes do not interfere with the typically GHz laser communications signal. Importantly, our system reduces transmitter power requirements by correcting small pointing errors and atmospheric-path aberrations. Of course the multiple-fiber amplifier array also enables power scaling. We describe our near- and far-field beam measurements in the laboratory.
- Publication:
-
Free-Space Laser Communication Technologies XVI
- Pub Date:
- June 2004
- DOI:
- 10.1117/12.529660
- Bibcode:
- 2004SPIE.5338...90B