Abstract

A dual wavelength laser (1.06 and 1.32 μm) has been constructed using the Nd:YAG rod, flashlamp head, and power supply from a General Photonics model TWO 45/46Q laser as shown in Fig. 1. The Nd:YAG rod and output coupler (0.37 reflecting at 1.06 and 0.72 at 1.32 μm) are common to both optical cavities. A dichroic beam splitter reflects the 1.06-μm radiation into one arm and transmits the 1.32-μm radiation into a second arm. Part of the output beam is directed to a monochromator with a Ge detector to verify lasing at 1.32 μm. The 1.06-μm light is detected with a Si photodiode. The temporal and amplitude characteristics of the Q-switched beams are controlled by an adjustable delay between the 1.32- and 1.06-μm Q-switches and by adjusting the losses in the 10.6-μm arm. This control is required since the Nd:YAG rod produces less gain at 1.32 μm than it does at 1.06 μm. This causes the 1.32-μm power to be lower and to take longer to build up during Q-switched operations. If the 1.06-μm pulse occurs earlier, lasing at 1.32 μm is suppressed. With a delay in the trigger pulse to the 1.06-μm Q-switch drive, it was possible to adjust the 1.06-μm pulse to be coincident in time with the 1.32-μm pulse.

© 1990 Optical Society of America