Abstract

We have built a Q-switched alexandrite laser which is injection seeded by a diode laser as an illumination source for a rubidium imaging atomic line filter.¹ The injection seeding source was a GaAlAs diode laser (Mitsubishi ML-4102) with low output power (3 mW) and narrow linewidth (<30 MHz) at 780 nm. The output frequency of the diode laser was stabilized to an atomic rubidium absorption line by using a reference rubidium cell and a frequency stabilization circuit whose phase sensitive detection of laser frequency modulation yielded the error signal needed for stabilization.² The alexandrite laser cavity length was controlled to match the cavity resonance frequency to the diode laser frequency. To do this one of the laser mirrors was mounted on a PZT driver, and the necessary information for feedback control was derived from the interference between the injection seeding beams going along different paths. A schematic diagram of the alexandrite laser and both feedback control loops is shown in Fig. 1.

© 1990 Optical Society of America