摘要 |
A tunable reference cavity (3) with two independently controllable mirrors (15, 16) is disclosed. The mirrors are mounted on respective piezoelectric crystals (18, 19) so that thermal expansion of the piezoelectric crystals moves the cavity mirrors in the same direction along a longitudinal axis of the reference cavity thereby reducing a change of the cavity length. Also disclosed is a system for locking and scanning the output of a laser cavity (2). An error signal is generated between an output of the laser cavity (28) and the transmission (28) of the laser through the external reference cavity (3). A dual piezo-actuated mirror (6b) permits processing of the error signal (26) with separate signal processing circuits (29a, 29b) used to provide an electrical feedback signal to the dual piezoelectric crystal (22, 23b). |