An electrically-controlled tunable intracavity frequency selector is demons
trated for the far-infrared p-Ge laser. The tunable laser mirror was driven
by a piezo-element inside a liquid helium bath. This design allows very sm
all controllable displacements of the tunable mirror that were impossible i
n previous mechanical systems. High-resolution spectroscopy of the laser ou
tput reveals the nature of mode-hop tuning characteristic for the tuning-el
ement construction used. (C) 2001 Elsevier Science B.V. All rights reserved
.