585results about "Laser monitoring arrangements" patented technology

A modular ultrafast pulse laser system is constructed of individually pre-tested components manufactured as modules. The individual modules include an oscillator, pre-amplifier and power amplifier stages, a non-linear amplifier, and a stretcher and compressor. The individual modules can typically be connected by means of simple fiber splices.

A hybrid laser source including a solid state laser driven by an array of fiber laser amplifiers, the inputs of which are controllable in phase and polarization, to compensate for distortions that arise in the solid state laser, or to achieve desired output beam properties relating to direction or focus. The output beam is sampled and compared with a reference beam to obtain phase and polarization difference signals across the output beam cross section, at spatial positions corresponding with the positions of the fiber laser amplifiers providing input to the solid state laser. Therefore, phase and polarization properties of the output beam may be independently controlled by predistortion of these properties in the fiber laser amplifier inputs.

A control system and apparatus for use with an ultra-fast laser is provided. In another aspect of the present invention, the apparatus includes a laser, pulse shaper, detection device and control system. A multiphoton intrapulse interference method is used to characterize the spectral phase of laser pulses and to compensate any distortions in an additional aspect of the present invention. In another aspect of the present invention, a system employs multiphoton intrapulse interference phase scan. Furthermore, another aspect of the present invention locates a pulse shaper and / or MIIPS unit between a laser oscillator and an output of a laser amplifier.

An optical nose for detecting the presence of molecular contaminants in gaseous samples utilizes a tunable seed laser output in conjunction with a pulsed reference laser output to generate a mid-range IR laser output in the 2 to 20 micrometer range for use as a discriminating light source in a photo-acoustic gas analyzer.

In a miniature Q-switched, pulsed laser, having a two arm folded resonator, Q-switching is effected by rapidly and reciprocally tilting a resonator mirror of the laser about an axis perpendicular to the axis of the laser resonator. The angular excursion of the tilting and the frequency of the tilting are selected cooperative with dimensions of the resonator to maximize energy and symmetry of intensity distribution in Q-switched pulses delivered by the laser. Rapid reciprocal tilting of the mirror is accomplished using a piezoelectrically-driven, MEMS scanner operated in a resonant mode.

To transmit energy without direct mechanical or electrical contact, a transmitter unit emits a laser beam onto a radiation receiver of a receiver unit including a photovoltaic cell arrangement surrounded by a ring-shaped reflector. A portion of the laser beam is reflected from the reflector back to the transmitter unit, where the received reflected signal is evaluated to determine the position of the laser beam impinging on the radiation receiver. The transmitter unit deflects the laser beam as necessary to impinge directly on the photovoltaic cell arrangement and track any relative motion of the receiver unit. The receiver unit orients the radiation receiver to optimize the energy reception. The position of the laser beam is modulated and the resulting variation of the reflected signal is evaluated to determine therefrom the position of the laser beam on the radiation receiver.

A system and method for providing a wavefront corrected high-energy beam of electromagnetic energy. In the illustrative embodiment, the system includes a source of a first beam of electromagnetic energy; an amplifier for amplifying said beam to provide a second beam; a sensor for sensing aberration in said second beam and providing an error signal in response thereto; a processor for processing said error signal and providing a correction signal in response thereto; and a spatial light modulator responsive to said correction signal for adjusting said beam to facilitate a correction of said aberration thereof. In more specific embodiments, the source is a laser and the sensor is a laser wavefront sensor. A mirror is disposed between said modulator and said sensor for sampling said beam. The mirror has an optical thin-film dielectric coating on at least one optical surface thereof. The coating is effective to sample said beam and transmit a low power sample thereof to said means for sensing aberration. The processor is an adaptive optics processor. The spatial light modulator may be a micro electro-mechanical system deformable mirror or an optical phased array. In the illustrative embodiment, the source is a master oscillator and the amplifier is a power amplifier beamline. An outcoupler is disposed between the oscillator and the amplifier.

A fibre laser system is disclosed comprising an optical fibre, a part of which is doped with a rare earth to form an optical gain medium; at least one laser diode; means for applying pump radiation from the laser diode to the optical gain medium and for generating a laser beam and delivery fibre means for delivering a laser beam to a workpiece, wherein the fibre laser is provided with at least one means for protecting one or more components from damage caused by errant radiation. Several different means of protection are disclosed.

To transmit energy without direct mechanical or electrical contact, a transmitter unit emits a laser beam onto a radiation receiver of a receiver unit including a photovoltaic cell arrangement surrounded by a ring-shaped reflector. A portion of the laser beam is reflected from the reflector back to the transmitter unit, where the received reflected signal is evaluated to determine the position of the laser beam impinging on the radiation receiver. The transmitter unit deflects the laser beam as necessary to impinge directly on the photovoltaic cell arrangement and track any relative motion of the receiver unit. The receiver unit orients the radiation receiver to optimize the energy reception. The position of the laser beam is modulated and the resulting variation of the reflected signal is evaluated to determine therefrom the position of the laser beam on the radiation receiver.

A laser system includes an optically pumped laser resonator that produces a fundamental-wavelength beam. A temperature-tuned frequency converter outside the laser resonator converts a portion of the fundamental-wavelength beam to a frequency-converted beam. The frequency converter includes at least one temperature-tuned optically nonlinear crystal. The power and position of the frequency-converted beam are dependent on the temperature of the optically nonlinear crystal and the optical pumping power. The power and position of the frequency-converted beam are monitored. The temperature of the optically nonlinear crystal is adjusted to maintain the frequency-converted beam at a predetermined position. The optical pump power is adjusted to maintain the power of the frequency-converted beam at a predetermined level.

The invention relates to a method for comprehensively measuring reflectivity, which comprises the following steps: dividing continuous incident laser beams into a reference beam and a detection beam, wherein the reference beam is focused on a photoelectric detector for direct detection and the detection beam is injected into an optical resonant cavity; using a cavity ring-down technology to measure an optical element with reflectivity more than 99%, respectively measuring a ring-down time tau 0 of an original optical resonant cavity output signal and a ring-down time tau 1 of the measured optical resonant cavity output signal after an optical element to be measured is added, and calculating the reflectivity R of the optical element to be measured; using the spectrophotometry to measure the reflectivity of the optical element to be measured when the R value is less than 99%; moving away an output cavity mirror; focusing detecting light reflected by a measuring mirror on the photoelectric detector for detecting while recording a light intensity signal ratio of the detection beam to the reference beam; and calibrating to further obtain the reflectivity R of the optical element to be measured. The device for measuring reflectivity can be used for measuring optical elements with any reflectivity and also can be used for realizing the high-resolution two-dimensional imaging of the reflectivity distribution of a large-aperture optical element.

A hybrid laser source including a solid state laser driven by an array of fiber laser amplifiers, the inputs of which are controllable in phase and polarization, to compensate for distortions that arise in the solid state laser, or to achieve desired output beam properties relating to direction or focus. The output beam is sampled and compared with a reference beam to obtain phase and polarization difference signals across the output beam cross section, at spatial positions corresponding with the positions of the fiber laser amplifiers providing input to the solid state laser. Therefore, phase and polarization properties of the output beam may be independently controlled by predistortion of these properties in the fiber laser amplifier inputs.

A laser and amplifier combination delivers a sequence of optical pulses. Pulses from the laser are temporally stretched by a pulse stretcher before amplification and temporally compressed by a pulse compressed after amplification. The pulse stretcher includes a diffraction grating on which pulses being compressed are incident. An arrangement is provided for measuring the carrier-envelope phase of the pulses and adjusting the incidence angle of pulses on the grating cooperative with the measurement such that the carrier envelope phase of the pulses in the sequence is about constant.

An optical amplifying apparatus, an optical output controlling method by the optical amplifying apparatus and an optical transmitting apparatus, in which an optical output constant control is possible irrespective of an optical input level even when power-on is detected or an optical signal inputted after supply of pump light is stopped is recovered. The optical amplifying apparatus has an pump light outputting unit, an optical amplifier amplifying an input optical signal with pump light from the pump light outputting unit, an output constant control unit controlling the pump light outputting unit to keep a level of the amplified optical signal constant, an optical input monitoring unit, a pump light level setting unit setting an optical level of the pump light based on a result of optical input monitoring from the optical input monitoring unit, a pump light monitor control unit monitoring a level of the pump light to control the pump light outputting unit so as to stabilize an output level of the pump light at an optical level set by the pump light level setting unit, an input disconnection detecting unit, and an operation control switching unit switching a control mode for pump light to an output constant control mode, a pump light control mode or a stop control mode.

A fiber laser system is provided with a laser cavity including at least a gain fiber, an output coupling mirror, and a saturable absorber mirror. A photo sensor detects leakage light passing through the saturable absorber mirror, for purposes of monitoring the performance of the laser system. The saturable absorber mirror may include a semiconductor saturable absorber having a Bragg reflector monolithically formed on one side thereof.

Methods and apparatus for the active control of a wavelength-swept light source used to interrogate optical elements having characteristic wavelengths distributed across a wavelength range are provided.

A novel broadly tunable optical parametric oscillator is described for use in numerous applications including multi-photon microscopy. The optical parametric oscillator includes at least one sub-picosecond laser pump source configured to output a pump signal having a wavelength of about 650 nm or less and at least one type II optical parametric oscillator in optical communication with the pump source and configured to generate a single widely tunable pulsed optical signal. In one application, an optical system is in optical communication with the optical parametric oscillator and configured to direct at least a portion of the optical signal to a specimen, and at least one analyzing device is configured to receive a signal from the specimen in response to the optical signal.

Embodiments of systems and methods are provided for a tunable laser device. The tunable laser device may include a diffraction grating connected to a pivot arm that pivots the diffraction grating about a pivot point to tune the laser device. In pivoting the diffraction grating about the pivot point, both the wavelength to which the diffraction grating is tuned and the length of the optical cavity may be changed. The length of the pivot arm may be selected to reduce the number of mode hops of the tunable laser device when tuning the laser device over its tuning range.

Wavefront control techniques are provided for the alignment and performance optimization of optical devices. A Shack-Hartmann wavefront sensor can be used to measure the wavefront distortion and a control system generates feedback error signal to optics inside the device to correct the wavefront. The system can be calibrated with a low-average-power probe laser. An optical element is provided to couple the optical device to a diagnostic / control package in a way that optimizes both the output power of the optical device and the coupling of the probe light into the diagnostics.

A fibre laser system is disclosed comprising an optical fibre, a part of which is doped with a rare earth to form an optical gain medium; at least one laser diode; means for applying pump radiation from the laser diode to the optical gain medium and for generating a laser beam and delivery fibre means for delivering a laser beam to a workpiece, wherein the fibre laser is provided with at least one means for protecting one or more components from damage caused by errant radiation. Several different means of protection are disclosed.

An arrangement for providing real-time, in-service OTDR measurements in an optical communication system utilizing distributed Raman amplification. One or more of the laser diodes used to provide the pump light necessary to create optical gain is modified to also generate short duration pulses that ride above or below the conventional pump light. These short duration pulses (which co-exist with the pump light within the optical fiber) are used in performing OTDR measurements, with a conventional processing system used to evaluate reflected pulses and create the actual OTDR measurements.

The optical system comprises: means for introducing a controlled negative or positive chirp to an incoming ultrashort laser pulse to be characterized; a nonlinear optical medium through which said chirped ultrashort laser pulse is propagated, wherein as a result of said propagation: different chirp values are introduced in the ultrashort laser pulse at different propagation distances along the nonlinear optical medium, and a transverse nonlinear signal is generated in a direction perpendicular to the propagation axis; analyzing means configured for recording a single-shot spectral image of said generated transverse nonlinear signal; and a processing module comprising one or more processors configured to execute a numerical iterative algorithm to said single-shot spectral image to retrieve the electric field, amplitude and phase, of the ultrashort laser pulse.

An optical amplifier including a pumping source for supplying pump light to an optical fiber transmission line is provided so that at least a part of the optical fiber transmission line produces Raman amplification to an optical signal. An optical filter unit for selectively switching between a first condition where the optical signal and the pump light are passed and a second condition where the optical signal is passed and the pump light is not passed is connected between the optical fiber transmission line and the optical amplifier. The power of the optical signal in the first condition is compared with that in the second condition, and the characteristics of the optical fiber transmission line, such as a splice loss therein, is evaluated according to the result of this comparison. In the second condition, the residual pump light is not supplied to the optical fiber transmission line, so that a measurement error due to Raman amplification can be eliminated to thereby allow accurate evaluation of the characteristics of the optical fiber transmission line.

A system and method for providing a wavefront corrected high-energy beam of electromagnetic energy. In the illustrative embodiment, the system includes a source of a first beam of electromagnetic energy; an amplifier for amplifying said beam to provide a second beam; a sensor for sensing aberration in said second beam and providing an error signal in response thereto; a processor for processing said error signal and providing a correction signal in response thereto; and a spatial light modulator responsive to said correction signal for adjusting said beam to facilitate a correction of said aberration thereof. In more specific embodiments, the source is a laser and the sensor is a laser wavefront sensor. A mirror is disposed between said modulator and said sensor for sampling said beam. The mirror has an optical thin-film dielectric coating on at least one optical surface thereof. The coating is effective to sample said beam and transmit a low power sample thereof to said means for sensing aberration. The processor is an adaptive optics processor. The spatial light modulator may be a micro electro-mechanical system deformable mirror or an optical phased array. In the illustrative embodiment, the source is a master oscillator and the amplifier is a power amplifier beamline. An outcoupler is disposed between the oscillator and the amplifier.

The invention relates to a method for determining at least one unknown laser beam parameter of a laser beam used for correcting errors of a transparent material including inducing a first persistent modification in the material by an interaction with the laser beam having a first set of laser beam parameters, measuring the induced first persistent modification of the material, calculating a second persistent modification in the material using a model describing persistent modifications in the material with a second set of laser beam parameters, wherein the first set of laser beam parameters comprises the second set of laser beam parameters and the at least one unknown laser beam parameter, setting up a target functional including the first persistent modification and the second persistent modification, and determining the at least one unknown laser beam parameter by minimizing the target functional.

The invention discloses a high-stability laser pumping source with an overtemperature protection function and belongs to the technical field electronic equipment. The laser pumping source structurally comprises a laser module (1), a power control module (2) and a temperature control module (3). The laser pumping source is characterized by further comprising a display driving module (3) structurally, and the power control module (2) is composed of a power setting module (21), a power sampling module (22), a PID operation module (23), an LD driving module (24), an overtemperature processing module (25) and a soft starting module (26). The laser pumping source is high in stability and has the functions of overtemperature alarming power-off and soft starting.

A laser beam is generated and transmitted within an enclosed pathway through at least one crystal optic at a power density that progressively degrades transmissivity of the crystal optic with accumulating fluence. The crystal optics are cooled below normal operating temperatures to slow the progressive degradation in the transmissivity of the crystal optics with the accumulating fluence or to accommodate a higher power density without correspondingly increasing the progressive degradation in transmissivity.