Coherent Lasersystems Gmbh & Co. Kg

Cobolt Ab

Coherent, Inc.

Cobalt Ab

Stefan Spiekermann

Håkan Karlsson

Georg Sommerer

Katrin Ekvall

Fredrik Laurell

Valdas Pasiskevicius

Jenni Nordborg

Sandra Johansson

Shunhua Wang

Renée Hansson

In a master oscillator plus power amplifier (MOPA) system, the oscillator is a passively Q-switched laser. The laser is triggered into passively Q-switched operation by operating an optical switch to resonantly couple back into the laser amplified stimulated emission generated by the amplifier.

MOPA with externally triggered passively Q-switched laser

A microcrystal laser for generating laser pulses has a laser resonator which has a laser medium arranged between two mirrors; and an arrangement for stabilizing the optical path length is provided. The laser resonator has a saturable absorber medium for pulse generation.

Microcrystal laser for generating laser pulses

A microcrystal laser assembly including a gain-crystal includes a frame having a high thermal conductivity. The frame has a base with two spaced apart portions extending from the base. The gain-crystal has a resonator output minor on one surface thereof. The gain-crystal is supported on the spaced-apart portions of the frame in the space therebetween. Another resonator minor is supported in that space, spaced apart from the output mirror, on a pedestal attached to the base of the frame. The pedestal and the frame have different CTE. Varying the frame temperature varies the spacing between the resonator minors depending on the CTE difference between the pedestal and the frame.

Wavelength-stabilized microcrystal laser

A master oscillator power amplifier (MOPA) system includes an oscillator having a neodymium-doped gadolinium vanadate gain-medium and delivering seed-pulses. A length of single mode fiber is used to broaden the spectrum of the seed pulse. An amplifier having a neodymium-doped yttrium vanadate gain-medium amplifies the spectrally broadened seed-pulses. The gain-spectrum of the amplifier partially overlaps the broadened pulse-spectrum, providing spectral selection of the seed-pulses in addition to amplification. This provides amplified output-pulses having a duration about one-third that of the corresponding seed-pulses.

Short-pulsed compact MOPA

A laser arrangement comprising a first and a second resonant cavity for generating a first and a second fundamental wavelength. A first and a second non-linear region are provided in the second cavity for sum-frequency mixing of the radiation generated in the first cavity and in the second cavity, and for frequency-doubling of the radiation generated in the second cavity, respectively.

Multiple wavelength laser arrangement

A method of generating coherent radiation, wherein a first fundamental beam of radiation from a four level laser and a second fundamental beam of radiation from a three level laser are mixed in a non-linear body to obtain an output beam at the sum frequency of the two fundamental beams. The invention also relates to an arrangement for carrying out the method.

Optical frequency mixing

A method and a device for generating visible coherent radiation is disclosed. The visible coherent radiation is generated by sum-frequency mixing of a first fundamental beam from a diode laser and a second fundamental beam from a diode-pumped solid-state laser. The mixing is performed by means of a quasi-phasematching element provided within the resonant cavity of the solid-state laser. The first fundamental beam is stabilized by providing feedback to the diode laser.

Coherent light source based on sum-frequency mixing

A lens arrangement for transforming a divergent, generally astigmatic laser beam from a diode laser into a beam having a high degree of rotational symmetry is disclosed. The arrangement comprises, in series, a first cylindrical gradient index lens arranged with its principal axes parallel to the principal axes of the astigmatic laser beam; a second cylindrical gradient index lens arranged with its principal axes parallel to the principal axes of the astigmatic laser beam; and a third cylindrical gradient index lens arranged with its principal axes rotated 45 degrees with respect to the principal axes of the astigmatic laser beam. The first and the second gradient index lenses have such refractive powers that both the fast and the slow axis of the astigmatic laser beam are converged to a focus inside the third gradient index lens.

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Hannover, Germany

Stefan Spiekermann