Highly achromatic, narrow linewidth distributed feedback dye laser pumped by a multimode laser

Highly achromatic operation of a computer-optimized distributed feedback dye laser is reported. Linewidths of between 320 and 500 MHz, a factor of up to 100 less than the pump laser linewidth, have been measured across a scanning range of 70 nm. The dependence of the laser linewidth on pump laser parameters such as linewidth and energy has also been studied. The wavelength dependence of the laser linewidth was well represented by a computer model, and the measured threshold was close to the value predicted by a rate equation model. A conversion efficiency of 20% was obtained