Share Email Print

Proceedings Paper

Realization of heterodyne acquisition and tracking with diode lasers at lambda=1.55 um
Author(s): Martin F. Hueber; Walter R. Leeb; Arpad L. Scholtz
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

We designed, realized, and tested a laboratory model of an optical intersatellite link employing InGaAS DFB semiconductor lasers operating at a wavelength of 1.55km. Heterodyne sensing was used for both the spatial acquisition and the spatial tracking processes. During the acquisition process spiral scanning of the transmitter area of uncertainty is performed. A microcomputer controls the receiver operation. For each spatial search position the local oscillator laser is swept through a predefined frequency uncertainty range until the beat signal appears at the desired intermediate frequency (IF=700MHz). A heterodyne quadrant detector was realized by using a four-sided reflecting pyramid to split the superimposed beam. During tracking, the microcomputer reads the tracking sensor output signals, calculates the required antenna correction, and feeds the appropriate signals to the beam steering unit. Thus we realized a digital tracking loop, whereas the intermediate frequency is stabilized by means of an analog control loop. The tracking sensor angular resolution -withoutusing a telescope - is 5rad, limited by the digital signal processing, at a detector field of view of lmrad. The typical tracking error measured for various system conditions amounts to less than 1/20 of the FOV, i.e. less than

Paper Details

Date Published: 1 May 1991
PDF: 8 pages
Proc. SPIE 1522, Optical Space Communication II, (1 May 1991); doi: 10.1117/12.46090
Show Author Affiliations
Martin F. Hueber, Technische Univ. Wien (Austria)
Walter R. Leeb, Technische Univ. Wien (Austria)
Arpad L. Scholtz, Technische Univ. Wien (Austria)

Published in SPIE Proceedings Vol. 1522:
Optical Space Communication II
Juergen Franz, Editor(s)

© SPIE. Terms of Use
Back to Top