Tunable dye laser with lumped–distributed feedback

Characteristics of a dye laser with a lumped–distributed feedback (LDFB) loop were investigated experimentally with the aim of optimization of the laser parameters under wavelength tuning conditions. An analysis was made of the characteristics of a system for pumping such lasers proposed earlier and of the conditions necessary to ensure LDFB. A tunable rhodamine 6G laser was built: its tuning range was 0.54–0.6 μm, the width of the emission line (after allowance for the instability) was 0.2 cm^– 1, and the maximum efficiency was 33%. Additional selection by a tunable intracavity Fabry–Perot etalon reduced the line width to 0.02 cm^– 1, but the efficiency decreased to 3%.