Mid-ir kerr lens mode locked laser with normal incidence mounting of polycrystalline tm:ii-vi materials and method for controlling parameters of polycrystalline tm:ii-vi kerr lens mode locked laser

Abstract

A Kerr Mode Locked ('KLM') laser is configured with a resonant cavity. The gain medium, selected from polycrystalline transition metal doped II-VI materials ('TM:II-VI), is cut at a normal angle of incidence and mounted in the resonant cavity so as to induce the KLM laser to emit a pulsed laser beam at a fundamental wavelength. The pulses of the emitted laser beam at the fundamental wavelength each vary within a 1.8-8 micron (“μm') wavelength range, have a pulse duration equal to or longer than 30-35 femtosecond (“fs”) time range and an average output power within a mW to about 20 watts (“W”) power range. The disclosed resonant cavity is configured with a plurality of spaced apart reflectors, two of which flank and are spaced from the gain medium which is pumped to output a laser beam at a fundamental wavelength and its higher harmonic wavelengths. The gain medium is mounted on a translation mechanism operative to controllably displace the gain medium along a waist of the laser beam. The displacement of the gain medium causes redistribution of a laser power between a primary output at the fundamental wavelength and at least one secondary output at the higher harmonic wavelength.