Influence of aperture effects on the stability of the emission wavelength of a tunable laser

An experimental investigation was made of the relationship between the emission spectrum of a pulsed tunable laser and the spatial as well as angular characteristics of the radiation field in a dispersive resonator cavity. It was found that in the case of laser pumping, which determined the structure of the excitation zone and also the instability of its position and the optical properties of the induced lens, the maximum stability of the center of gravity of the spectrum was achieved by suppression of asymmetric aperture limitations in the dispersion plane of the resonator. In the case of a laser utilizing a solution of 6-aminophenalenone and characterized by a relatively small angular dispersion of the resonator (4 ang.min/nm) the rms deviation of the wavelength did not exceed 0.3 pm when the line width was 6 pm.