This is an optimized oscillator architecture with a cavity length of 75 mm. The angle of incidence at the grating, deployed in Littrow configuration, is about 77 degrees. This cavity yields a laser beam with a STM profile and a divergence 1.5 times the diffraction limit. This oscillator lases in a SLM at a linewidth of 350 MHz. The tuning range is 550-603 nm.
Excitation is longitudinal to the optical axis of the cavity.
A laser linewidth of 350 MHz corresponds to about 0.0004 nm at a wavelength of 590 nm. To date this is the narrowest laser linewidth reported for solid-state dye laser oscillators. This class of MPL grating solid-state dye laser oscillator yields smooth STM beam profiles as illustrated in the following figure. A Fabry-Perot interferogram, from the same oscillator, illustrates typical SLM emision at a linewidth of 700 MHz. In this case the cavity length limits the intracavity mode spacing to 3 GHz.