Coherent, Inc.

Robert Henschke

Anthony J DeMaria

Lanny Laughman

Joel Fontanella

Leon A Newman

John T Kennedy

Richard A Hart

Peter P Chenausky

Eric R Mueller

Vernon A Seguin

An improved laser system includes a sealed-off, RF excited, diffusion cooled, high pressure, short pulsed, high peak power waveguide and slab COlaser that avoids problems typically associated with obtaining a diffused discharge at high gas pressures, without arcing and without corona, while maintaining the unsaturated gain and gas temperature experienced at low pressures and scaling to higher pressures. Such a system has a long operating life-time, and is capable of operation at high gas pressures to obtain relative fast rise and fall time pulses. The system emits relatively short pulse widths, with pulse energies up to and exceeding 30 mJ, with reasonably high pulse repetition rates. The system also has a low pulsed RF power duty cycle, thereby enabling the generation of high peak power pulses, as well as reasonable average power and reasonably high peak powers.

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A COlaser reference oscillator (RO) can provide injection seeding to a Q-switched (QS) or Q-switched cavity dumped (QSCD) COlaser, where the output frequency of the RO laser is locked to the peak of the laser line by the use of appropriate electronics to dither one of the resonator mirrors of the reference oscillator. This injected radiation seeds the radiation building up within the Q-switched laser cavity, such that the oscillating frequency favors the wavelength of the injected radiation. An electronic feedback control circuit can be used to lock an axial mode of the Q-switched laser to line center. The change in build-up time of the pulses within the QS laser can be used to maintain cavity length at a value that enables oscillating at the peak of the same laser line that is injected into QS laser.

This disclosure discusses techniques for obtaining wavelength selected simultaneously super pulsed Q-switched and cavity dumped laser pulses utilizing high optical damage threshold electro-optic modulators, maintaining a zero DC voltage bias on the CdTe electro-optic modulator (EOM) so as to minimize polarization variations depending on the location of the laser beam propagating through the CdSe EOM crystal, as well as the addition of one or more laser amplifiers in a compact package and the use of simultaneous gain switched, Q-switched and cavity dumped operation of COlasers for generating shorter pulses and higher peak power for the hole drilling, engraving and perforation applications.

Q-switched, cavity dumped laser systems for material processing

A simultaneously super pulsed Q-switched CO laser system for material processing is disclosed. The system comprises sealed-off folded waveguides with folded mirrors that are thin film coated to select the output wavelength of the laser. The system also comprises a plurality of reflective devices defining a cavity; a gain medium positioned within the cavity for generating a laser beam; a cavity loss modulator for modulating the laser beam, generating thereby one or more laser pulses; a pulsed signal generation system connected to the cavity loss modulator for delivering pulsed signals to the cavity loss modulator thereby controlling the state of optical loss within the cavity; a control unit connected to the pulsed signal generation system for controlling the pulsed signal generation system; and a pulse clipping circuit receptive of a portion of the laser beam and connected to the pulsed signal generation system for truncating a part of the laser pulses.

Q-switched CO2 laser for material processing

This disclosure discusses techniques for obtaining wavelength selected simultaneously super pulsed Q-switched and cavity dumped laser pulses utilizing high optical damage threshold electro-optic modulators, maintaining a zero DC voltage bias on the CdTe electro-optic modulator (EOM) so as to minimize polarization variations depending on the location of the laser beam propagating through the CdSe EOM crystal, as well as the addition of one or more laser amplifiers in a compact package and the use of simultaneous gain switched, Q-switched and cavity dumped operation of CO lasers for generating shorter pulses and higher peak power for the hole drilling, engraving and perforation applications.

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East Hampton, CT, United States of America

Robert Henschke