Coherent Patent Applications

IMPEDANCE-MATCHING CIRCUITS FOR MULTI-OUTPUT POWER SUPPLIES DRIVING CO2 GAS-DISCHARGE LASERS

Granted: April 12, 2012
Application Number: 20120086519
Electrical apparatus for connecting a radio frequency power-supply having two outputs to a load includes two radio frequency transmission-lines, each one connected to a corresponding power-supply output. A transformer arrangement connects the two transmission-lines to the load. Each transmission-line includes a series-connected pair of twelfth-wave transmission-line sections. The series-connection between the twelfth wave transmission-line sections in one transmission line is connected…

LARGE-FIELD UNIT-MAGNIFICATION CATADIOPTRIC PROJECTION SYSTEM

Granted: March 15, 2012
Application Number: 20120063010
A unit magnification projection optical system includes, listed in order along a system axis, a mirror, a lens group having negative power and a lens group having positive power. The optical system is a symmetric system, with an object plane on one side of the system axis and an object plane on an opposite side of the system axis. The object and image planes are spaced apart from the positive lens group by a working distance greater than 100 millimeters.

INTRA-CAVITY SUM-FREQUENCY MIXING USING SOLID-STATE AND SEMICONDUCTOR GAIN-MEDIA

Granted: March 8, 2012
Application Number: 20120057608
A two-resonator laser arrangement for provides visible-wavelength radiation by sum-frequency mixing two different wavelengths of radiation circulating in the resonators in an optically nonlinear crystal located in the resonators. One of the resonators includes a solid-state gain-medium providing of one the two wavelengths and the other resonator includes a semiconductor gain-medium providing the other of the two wavelengths. A very short excited-state lifetime of the semiconductor…

LINE-PROJECTION APPARATUS FOR ARRAYS OF DIODE-LASER BAR STACKS

Granted: March 8, 2012
Application Number: 20120057345
In optical apparatus for illuminating a mask-plane with a line of light, a light source includes four fast-axis stacks of laser diode bars. One optical arrangement collects light beams from all of the diode-laser bar stacks, homogenizes and expands the beams in the fast-axis direction of the diode-laser bar stacks and partially overlaps the homogenized and expanded beams in the fast-axis direction. Another optical arrangement homogenizes the sum of the partially overlapped beams and…

HERMETICALLY-SEALED RF FEED-THROUGH WITH INTEGRATED CAPACITOR

Granted: February 9, 2012
Application Number: 20120033703
A carbon-dioxide (CO2) gas-discharge slab laser includes elongated discharge-electrodes in a sealed enclosure. Radio Frequency (RF) power is supplied to the electrodes via an impedance matching network and a co-axial electrical low inductance transmission line feed-through sealed to the enclosure. The feed-trough includes two spring contacts which are configured to be spring compression push-fit in grooves in edges of the discharge-electrodes. A central conductor of the feed-through is…

OPTICAL PUMPING OF A SOLID-STATE GAIN-MEDIUM USING A DIODE-LASER BAR STACK WITH INDIVIDUALLY ADDRESSABLE BARS

Granted: February 9, 2012
Application Number: 20120033692
A diode-laser bar stack includes a plurality of diode-laser bars having different temperature dependent peak-emission wavelengths. The stack is arranged such that the bars can be separately powered. This allows one or more of the bars to be “on” while others are “off”. A switching arrangement is described for selectively turning bars on or off, responsive to a signal representative of the temperature of the diode-laser bar stack, for providing a desired total emission spectrum.

HIGH-PRECISION SYNCHRONIZATION OF PULSED GAS-DISCHARGE LASERS

Granted: February 9, 2012
Application Number: 20120033689
Two excimer lasers have individual pulsing circuits each including a storage capacitor which is charged and then discharged through a pulse transformer to generate an electrical pulse, which is delivered to the laser to generate a light pulse. The time between generation of the electrical pulse and creation of the light pulse is dependent on the charged voltage of the capacitor. The capacitors are charged while disconnected from each other. The generation of the electrical pulses is…

ADVANCED SHIFTING ALGORITHM FOR PROLONGING THE LIFE OF AN OPTICALLY NONLINEAR CRYSTAL

Granted: February 9, 2012
Application Number: 20120033291
In a shifting algorithm for an optically nonlinear crystal arranged to frequency-convert beam of radiation, the location of one or more defects in the crystal is recorded as an exclusion zone. The location of the beam is stepped incrementally over a surface around a closed or open loop path in increments less than a beam dimension. The path is arranged such that the beam does not enter the exclusion zone.

MODULATION METHOD FOR DIODE-LASER PUMPED LASERS

Granted: January 26, 2012
Application Number: 20120020380
A method of operating a digitally modulated solid state laser is disclosed. The laser is optically pumped by a current-supply driven diode-laser radiation and with output-power stabilized at a desired value by a light regulator cooperative with a power monitor and the current source is disclosed. When the laser is turned on, the current-source is enabled and the light-regulator is disabled. A current regulator allows current from the current-supply to increase until the monitored power…

HYBRID FIBER-MOPA

Granted: December 22, 2011
Application Number: 20110310468
A master oscillator power-amplifier stages includes multiple stages of fiber-amplification with a final power amplifier stage in the form of a multi-pass amplifier. With a thin-disk gain medium in one example the thin-disk amplifier includes a common optical arrangement for providing multiple incidences of radiation to be amplified and multiple incidences of a pump-radiation beam on the thin-disk gain medium.

IMPEDANCE-MATCHING TRANSFORMERS FOR RF DRIVEN CO2 GAS DISCHARGE LASERS

Granted: November 24, 2011
Application Number: 20110285473
In a CO2 gas discharge laser energized by a radio frequency (RF) power source a transformer having selectively variable output impedance is used to match output impedance of the power source to the impedance of discharge electrodes of the laser. A similar transformer can be used to impose a selective variable phase-shift on the RF power from the source. The variable impedance transformer can also be used for impedance matching between amplifier stages in the power source.

POLARIZATION MAINTAINING MULTI-PASS IMAGING SYSTEM FOR THIN-DISK AMPLIFIERS AND OSCILLATORS

Granted: October 13, 2011
Application Number: 20110249698
Multi-pass optical imaging apparatus includes a concave mirror in combination with two retro-reflecting mirror pairs and at least one reflective surface. The mirror, the retro-reflecting minor pairs and the reflecting surface are arranged such that a light-ray input into the apparatus parallel to and spaced apart from the optical axis of the concave mirror and incident on the concave mirror is caused to be incident on the thin-disk gain-medium at least four times, with each of the four…

ARRANGEMENT FOR RF POWER DELIVERY TO A GAS DISCHARGE LASER WITH CASCADED TRANSMISSION LINE SECTIONS

Granted: August 11, 2011
Application Number: 20110194581
RF power is transmitted to a CO2 gas discharge laser form a source of RF power via a series combination of transmission line sections. The lengths and characteristic impedances of the transmission line sections are selected to transform the impedance of the RF power source to the operating impedance of the laser.

TWO FREQUENCY RESONANTLY EXCITED MEMS MIRROR FOR DIODE-LASER MARKER

Granted: August 4, 2011
Application Number: 20110188103
Apparatus for marking a bitmap image on tape includes a scanning mirror which is incorporated in a micro-electro-mechanical system (MEMS). The MEMS is torsionally resonant at two frequencies one being about three time the other. The MEMS is excited to resonance by applying an AC signal to the actuators, causing the mirror to oscillate. The AC signal has components at the two frequencies. The magnitude and phase-relationship of the components can be selected such that the mirror…

CO2 LASER OUTPUT POWER CONTROL DURING WARM-UP

Granted: July 28, 2011
Application Number: 20110182319
A CO2 gas discharge laser includes a housing enclosing spaced-apart electrodes and a lasing gas. A laser resonator extends between the spaced-apart electrodes. An RF power supply provides RF power for creating a discharge in the lasing gas, causing laser radiation to be delivered by the laser resonator. The power of the output radiation is directly dependent on the RF power provided to the electrodes and inversely dependent of the temperature of the gas discharge. A signal representative…

DIODE-LASER MARKER WITH ONE-AXIS SCANNING MIRROR MOUNTED ON A TRANSLATABLE CARRIAGE

Granted: July 7, 2011
Application Number: 20110164104
Apparatus for marking a bitmap image on tape includes a source of a modulatable laser-beam. The beam is directed to an oscillating mirror on a carriage translatable across the width direction of the tape. The oscillating mirror directs the beam to a focusing lens mounted on the carriage. The focusing lens is arranged to focus the beam to a focal-spot on the tape. As the carriage is translated, the focal-spot is swept reciprocally in a wave-like path across the tape. Modulation of the…

RESONANT PUMPING OF THIN-DISK LASER WITH AN OPTICALLY PUMPED EXTERNAL-CAVITY SURFACE-EMITTING SEMICONDUCTOR LASER

Granted: June 23, 2011
Application Number: 20110150013
Laser apparatus comprises a solid-state laser-resonator including a thin-disk solid-state gain-medium. The thin-disk gain medium is optically pumped using radiation circulating in an OPS-laser resonator. The solid-state laser-resonator can be a passively mode-locked or actively Q-switched laser-resonator.

BEAM STEERING USING A THERMALLY ANISOTROPIC MEDIUM

Granted: June 2, 2011
Application Number: 20110128609
Apparatus for steering a beam of radiation includes a thermally anisotropic element configured such that the shape of the optical element can be varied by varying the temperature of the element. The beam is reflected from or transmitted through the element in a manner such that the direction of the beam on leaving the element can be varied by the change of shape resulting from the temperature variation.

ACOUSTO-OPTICALLY Q-SWITCHED CO2 LASER

Granted: May 26, 2011
Application Number: 20110122897
A pulsed CO2 laser is Q-switched by an intracavity acousto-optic (AO) Q-switch including an AO material transparent at a fundamental wavelength of the laser. In one example the AO material is germanium.

Simulating Phase-Coherent GNSS Signals

Granted: May 12, 2011
Application Number: 20110109506
A method and apparatus for simulating radio-frequency Global Navigation Satellite System (GNSS) signals that are carrier-phase and code-phase aligned with ambient GNSS signals at a user-specified location in the vicinity of the simulator. Such phase alignment allows the synthesized signals to be made to appear substantially the same as the authentic signals to a target receiver, allowing the target receiver to transition seamlessly between authentic and simulated signals. The method is…