Using a special cell design for low dye concentrations that limits the thickness of the transversely pumped dye solution by an exit window for the pump beam (1) sharp longitudinal modes with steep spectral line shapes develop because of the low small signal gain, and (2) the beam profile follows a Gaussian over 3 decades because both pump windows act as a mode selective aperture. The rest of the pump beam excites a second dye solution, separated from the first by a 1-cm thick window, so that a variety of different ring designs can easily be tested. The tendency of the linear resonator to form a double peaked output cross section was not observed with the running wave.
© 1983 Optical Society of America
Johannes Hildebrandt, "Some ring-dye-laser designs incorporating a low-concentration double dye cell for 20-nsec pump pulses," Appl. Opt. 22, 2930-2932 (1983)