A hybrid resonator and amplifier combination for generating a high energy output signal. The combination comprises a beam splitter for splitting a pump laser beam into first and second portions. The second portion beam being conveyed to a resonator which operates in a single transverse mode to generating a signal wavelength beam. An output coupler of the resonator allows a first portion of the signal wavelength beam to pass therethrough while retaining a second portion of the signal wavelength beam within the resonator. A system dichroic mirror receives and directs both the first portion and the signal wavelength beam toward an amplifier. The amplifier receives both the first portion and the signal wavelength beam. The first portion, upon passing through the amplifier, creates gain which is used by the amplifier to amplify the signal wavelength beam generate the high energy output signal.

Systems and methods for spectrally broadening seed pulses with a single pass laser amplifier are disclosed. A bulk TM:II-VI polycrystalline material with combined gain and nonlinear characteristic provides passive (cold) spectral broadening of high power seed pulses. Continuous pumping provides more significant spectral broadening. In particular, pulsed pumping of TM:II-VI polycrystalline material (e.g. Cr2+:ZnS, Cr2+:ZnSe, and Cr2+:CdSe) is shown to provide significant spectral broadening to the super continuum generation SCG level. Pulse picking, pump sources, master oscillators and various optical components are described.

A method of generating fs laser pulses (1), includes steps of creating a circulating light field in a resonator cavity (10) with multiple resonator mirrors (11-18) by pumping at least one gain medium (21, 22) included in the resonator cavity (10), and passing the circulating light field through a first Kerr medium (31) included in the resonator cavity (10), so that the fs laser pulses (1) are formed by self-amplitude modulation of the circulating light field, wherein the resonator cavity (10) includes at least one supplementary Kerr medium (32-36) enhancing the self-amplitude modulation of the circulating light field, and each of the first Kerr medium (31) and the at least one supplementary Kerr medium (32-36) provide different non-linear Kerr lens contributions to the self-amplitude modulation of the circulating light field. Laser pulse source apparatus (100) for generating fs laser pulses (1) is also described.

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 (m) 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.