An apparatus for emitting electromagnetic radiation includes a gain element, an optical arrangement defining a resonator and arranged to re-direct radiation emitted by the gain element along a beam path back onto the gain element, the optical arrangement including an output coupler configured to couple a portion of the radiation in the resonator out of the resonator, and a pump arrangement configured to pump the gain element. The optical arrangement further includes a passive device placed in the resonator in the beam path, the passive device having at least two surface portions at an angle to each other. The passive device is arranged to direct first radiation portions and second radiation portions of the radiation, which first and second radiation portions are incident on different ones of the surface portions, to be spatially separated. The apparatus is suitable as a source of dual-comb pulsed laser radiation.

A method for generating femtosecond vortex beams with high spatial intensity contrast, where a noncollinearly pumped HG beam femtosecond laser generates femtosecond HG beam and a cylindrical lens mode converter converts the femtosecond HG beam to femtosecond LG vortex beam. The HG beam femtosecond laser comprises a pump source, a gain medium, a saturable absorption mirror as mode-locker, and an output coupler with a noncollinear angle between the laser beam and the pump beam in the gain medium, which enables the laser to generate pure, order-tunable femtosecond HG beams. Femtosecond vortex beams obtained after the cylindrical lens converter have high-intensity-contrast, and are topological charge-tunable.

A passively mode-locking laser and corresponding method is described. The laser comprises a resonator (2) terminated by first (3) and second (4) mirrors and folded by a third (5) and fourth (6) mirror. The third mirror comprises a reflector (14) surmounted by a multilayer semiconductor gain medium (15) including at least one quantum well layer while the second mirror (4) comprises an intensity saturable mirror. The resonator is configured to provide a cross sectional area of an intra cavity resonating field on the intensity saturable mirror that is greater than or equal to a cross sectional area of the intra cavity resonating field on the multilayer semiconductor gain medium. This arrangement provides a passively mode-locking laser that exhibits increased stability when compared to those systems known in the art.

An apparatus for generating and amplifying laser beams at approximately 1 micrometer wavelength is disclosed. The apparatus includes an ytterbium-doped gain-crystal pumped by an ytterbium fiber-laser. The fiber-laser enables a pump wavelength to be selected that minimizes heating of the gain-crystal. The apparatus can be configured for generating and amplifying ultra-fast pulses, utilizing the gain-bandwidth of ytterbium-doped gain-crystals.

A laser according to an exemplary embodiment of the present invention includes a pump laser outputting laser light, and a laser resonator including a laser crystal and an acoustic optical modulator and resonating the laser light output from the pump laser, wherein the pump laser is a Nd:YAG, and the laser crystal is Ti:Sapphire.

A passively mode-locking laser and corresponding method is described. The laser comprises a resonator (2) terminated by first (3) and second (4) mirrors and folded by a third (5) and fourth (6) mirror. The third mirror comprises a reflector (14) surmounted by a multilayer semiconductor gain medium (15) including at least one quantum well layer while the second mirror (4) comprises an intensity saturable mirror. The resonator is configured to provide a cross sectional area of an intra cavity resonating field on the intensity saturable mirror that is greater than or equal to a cross sectional area of the intra cavity resonating field on the multilayer semiconductor gain medium. This arrangement provides a passively mode-locking laser that exhibits increased stability when compared to those systems known in the art.

In a method, a laser pump module is set to a first power mode and pump energy is output at a first power level through the activation of a first subset of laser diodes. Laser light is emitted from a gain medium at the first power level in response to absorption of the pump energy. An operator input corresponding to a power mode setting is received. The laser pump module is switched to a second power mode and pump energy is output at a second power level through the activation of a second subset of the laser diodes. Laser light is emitted from the gain medium at the second power level in response to absorption of the pump energy.

Apparatus and methods for producing ultrashort optical pulses are described. A high-power, solid-state, passively mode-locked laser can be manufactured in a compact module that can be incorporated into a portable instrument for biological or chemical analyses. The pulsed laser may produce sub-100-ps optical pulses at a repetition rate commensurate with electronic data-acquisition rates. The optical pulses may excite samples in reaction chambers of the instrument, and be used to generate a reference clock for operating signal-acquisition and signal-processing electronics of the instrument.

An apparatus for generating and amplifying laser beams at approximately 1 micrometer wavelength is disclosed. The apparatus includes an ytterbium-doped gain-crystal pumped by an ytterbium fiber-laser. The fiber-laser enables a pump wavelength to be selected that minimizes heating of the gain-crystal. The apparatus can be configured for generating and amplifying ultra-fast pulses, utilizing the gain-bandwidth of ytterbium-doped gain-crystals.

A laser according to an exemplary embodiment of the present invention includes a pump laser outputting laser light, and a laser resonator including a laser crystal and an acoustic optical modulator and resonating the laser light output from the pump laser, wherein the pump laser is a Nd:YAG, and the laser crystal is Ti:Sapphire.