Gain in DTTC-methanol solution as a function of pump power, wavelength, and time

Abstract

The single-pass gain of a 4 × 10−5 M/l solution of 3,3′-diethylthiatricarbocyanine iodide in methanol optically pumped by a giant-pulse ruby laser was measured as a function of pump power, wavelength, and time. Pump power was varied over a range of 0–7 MW and the wavelength range was 7850–8075 Å. The gain is seen to have strong dependence on the instantaneous pump power. The dependence of gain on pump power is plotted from the experimental data for six wavelengths in the region investigated, and is also discussed theoretically. The spontaneous decay rate from the excited state and the cross section for stimulated emission are also obtained from the theory. The low signal gain coefficient and the gain saturation value are tabulated for each wavelength investigated.