Spatial mode matching efficiencies for heterodyned GaAlAs semiconductor lasers

High spatial mode matching efficiencies are experimentally demonstrated when open-loop frequency-stabilized GaAlAs semiconductor lasers are heterodyned on silicon p-i-n detectors. Repeatable values of 75% are obtained using two independent lasers. The mode-matching efficiency increases to 90% when a single modulated laser is self-heterodyned using an unequal-path-length Mach-Zehnder interferometer. Experimental data are shown to match closely with theoretical predictions.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>