A narrowband grazing incidence pulsed dye laser improved by using an active multiregion

A novel and simple laser cavity is proposed in which the active medium is separated spatially into three regions in a single dye cell. This configuration permits to improve laser performance in spectral linewidth, purity and energy conversion. Using only one 5 cm-grazing incidence grating as a selective element, a tunable narrow band dye laser has been constructed having a simple-mode spectrum of about 750 MHz depending on dye concentration (5 x 10^-4 M-10^-3 M). Continuous scanning of a 1.3 GHz (FWHM) line over the entire lasing region of the dye is obtained with an efficiency of 6%. The advantages of using an active multiregion are discussed in relevance to possible applications.