ABSTRACT
We report a narrow-linewidth, tunable, gain-switched Cr:ZnSe laser operating between 2255 and 2455 nm. The spectral width of the laser was reduced from 125 nm to 0.3 nm by using injection seeding. Seeding was achieved with a second tunable CW Cr:ZnSe laser. The output wavelength was varied by tuning the wavelength of the seed laser. The seeded oscillator produced as high as 157 µJ pulses with 598 µJ incident pump pulse energy at a repetition rate of 1 kHz. The slope efficiency was determined to be 26%.
ABSTRACT
We describe a cw Kerr-lens mode-locked Cr(2+):ZnSe laser pumped by a 1800 nm thulium fiber laser. The astigmatically compensated asymmetric x cavity contained a 2.4-mm-long Cr(2+):ZnSe sample with a pump absorption coefficient of 11.6 cm(-1) and was operated with a 1% output coupler. The dispersion compensation was achieved by using a MgF(2) prism pair. During Kerr-lens mode-locked operation, we could generate 95 fs pulses at a pulse repetition rate of 94.3 MHz and with 40 mW of output power. The center wavelength of the pulses was 2420 nm. The pulses had a spectral width of 69 nm and a time-bandwidth product of 0.335, which is close to the transform limit for hyperbolic secant pulses.