Abstract: A laser (100) for outputting laser radiation includes a lasing material (110) in a resonant cavity (20) adapted for supporting a given lasing mode of oscillation. The laser (100) furthermore has at least one laser mirror (124) including a transparent portion for transmitting only a part of a beam of the laser (100) substantially smaller than the dimension of the beam of the laser (100) and the laser (100) includes a mode switching device (120) adapted to induce a change in the transmitted part of the beam, for altering the given lasing mode. A corresponding laser mirror (124), controller and a method for controlling a laser (100) also are described.

Abstract: A laser irradiation device includes: a laser light source; a mirror that reflects a part of light output from the laser light source and allows the remainder to pass; an optical detector that detects reflection light reflected by the mirror; and a feedback control circuit that receives a signal output from the optical detector and controls the output of the laser light source to keep a signal intensity constant, wherein a thickness of the mirror is set such that a distance between a beam spot of the reflection light reflected by a front surface of the mirror on the detector and a beam spot of reflection light reflected by a back surface of the mirror on the detector is equal to or more than a predetermined value.

Abstract: The present invention relates to an atomic frequency acquisition device comprising a gas cell (400) filled with an atomic gas, a laser light source (100) emitting a laser beam which enters the gas cell (40) and excites a first energy transition of the atomic gas, a local oscillator (700) for generating an oscillator frequency in a frequency range including a frequency of a HFS transition of the atomic gas, and a modulator (600) modulating the laser light source (100) so as to emit laser radiation modulated with the oscillator frequency. An optical reflector (500) is arranged behind the gas cell (400) to reflect the laser beam after passage through the atomic gas so as to re-enter the laser cavity. A photodetector (200) detects beat frequencies caused by self-mixing interference within the laser cavity.

Abstract: An optical phase-locked loop (OPLL) comprising a phase-frequency detector; first and second lasers; a local oscillator; a detector and a low pass filter; operably connected in a circuit comprising a feedback path. The OPLL can also include a pre-scaler, a second local oscillator and a mixer.

Abstract: A highly portable, high-powered infrared laser source is produced by intermittent operation of a quantum cascade laser power regulated to a predetermined operating range that permits passive cooling. The regulation process may boost battery voltage allowing the use of a more compact, low-voltage batteries.

Abstract: The present invention comprises, in various embodiments, systems and methods for shutting down a laser system in an intelligent and flexible manner. An intelligent laser interlock system includes both hardwired components, and intelligent components configured to execute computing instructions. The hardwired components and the intelligent components are configured to shutdown the laser system to one or more alternative shutdown states in response to one or more interlock signals.

Abstract: The present invention provides a semiconductor laser that operates with a frequency feedback control loop for frequency-noise reduction. The frequency-reduction architecture utilizes a homodyne optical phase demodulation approach. Such phase demodulation can be implemented with help of an unbalanced Michelson interferometer with fiber optics delay and symmetrical ‘n×n’ optical coupler. The entire demodulator is packaged in a small form-factor package which doesn't have any mechanical resonance in the sensing bandwidth, and has very low sensitivity to the external acoustic or vibration induced noise sources.

Abstract: An optoelectronic swept-frequency semiconductor laser coupled to a microfabricated optical biomolecular sensor with integrated resonator and waveguide and methods related thereto are described. Biomolecular sensors with optical resonator microfabricated with integrated waveguide operation can be in a microfluidic flow cell.

Abstract: Particular embodiments of the present invention relate generally to semiconductor lasers and laser projections systems and, more particularly, to schemes for controlling semiconductor lasers. According to one embodiment of the present invention, a laser having a gain section, a phase section and a wavelength selective section is configured for optical emission of encoded data. The optical emission is shifted across a plurality of laser cavity modes by applying a quasi-periodic phase shifting signal I/V? to the phase section of the semiconductor laser. The amplitude of the quasi-periodic signal transitions periodically between a maximum drive level and a minimum drive level at a frequency that varies randomly over time.

Abstract: A highly portable, high-powered infrared laser source is produced by intermittent operation of a quantum cascade laser power regulated to a predetermined operating range that permits passive cooling. The regulation process may boost battery voltage allowing the use of a more compact, low-voltage batteries.

Abstract: The present invention relates to a laser processing apparatus and the like having a structure for implementing at the same time both an efficient laser processing in the place where a laser beam is difficult to reach and a laser processing without damages in the place where the laser beam is easy to reach. This laser processing apparatus comprises a laser light source, an irradiation optical system applying a laser beam to an object while scanning the laser beam, a photo-detector detecting the laser beam applied from the irradiation optical system, and a control section of making switching between a continuous oscillation and a pulse oscillation of the laser beam at the laser light source.

Abstract: A light source device including a semiconductor light emitting element and a control section for controlling the semiconductor light emitting element in accordance with an input value. The control section includes a supply section that supplies the semiconductor light emitting element with a drive current based on the input value and an estimated threshold current of the semiconductor light emitting element, and an estimation section that obtains the estimation of the threshold current using the drive current and the amount of light detected to be emitted from the semiconductor light emitting element.

Abstract: A method of estimating an injection power of seed light injected into an injection-seeded transmitter. A back face monitoring (BFM) response of the injection-seeded transmitter is determined, and data representative of the BFM response stored in a memory. During run-time, a controller of the injection-seeded transmitter, detects a temperature of the injection-seeded transmitter and an instantaneous BFM current. BFM response data is obtained from the memory based on the detected temperature, and the seed light injection power estimated based on the obtained data and the detected instantaneous BFM current.

Abstract: The radiance of a laser is a function of drive current. The radiance is also a function of other factors, such as age and temperature. A laser projection device adjusts laser drive parameters using a gradient descent operation. The device parameters may be adjusted iteratively and periodically. The period may be shorter or longer than a scan line in a video image.

Abstract: Output pulses from an optical system having a seed source and an optical amplifier coupled to the seed source may be controlled by controlling a power of a seed signal from the seed source. The seed signal may be varied between a minimum value and a maximum value in a way that the seed signal exhibits one or more pulse bursts. Each pulse burst may contain one or more pulses. During an inter-pulse period between successive pulses within a pulse burst or between successive pulse bursts, the power of the seed signal may be adjusted to an intermediate value that is greater than the minimum value and less than the maximum value. The intermediate value is chosen to control a gain in the optical amplifier such that a pulse or pulse burst that follows the period exhibits a desired behavior.

Abstract: A temperature compensation method for laser power in an optical disk drive is provided. A predetermined linear-fitting power curve and a temperature-changing slope curve are previously stored in the optical disk drive. Firstly, an output of laser power is controlled according to the predetermined linear-fitting power curve to read/write data. Next, the temperature of the disk drive is detected. Then, whether the temperature has changed is checked. If the temperature has not changed, the method continues to read/write data. If the temperature has changed, the method obtains a relative slope from the slope curve by use of the temperature of the disk drive, displaces the slope of the predetermined linear-fitting power curve with the obtained relative slope to form a new linear-fitting power curve for replacing the predetermined linear-fitting power curve, and controls the output of laser power.

Abstract: A laser control method includes the steps of: using a laser control circuit which includes a constant current circuit that maintains a constant current flowing through a semiconductor laser element, and which includes an adder and a multiplier connected to a stage preceding the constant current circuit, and using detection means for calibration for detecting an applied laser output; calculating, on the basis of a detection signal output from the detection means, a reference bias value and a reference gain value for obtaining a specified laser output with respect to a specified input to the multiplier; inputting the reference bias value and the reference gain value to the adder and the multiplier, respectively; and controlling the applied laser output from the semiconductor laser element by performing calibration.

Abstract: The present invention relates to a method of measuring backward light, which is constructed for checking, prior to laser processing, backward light that propagates backward through an isolator included in a laser processing apparatus. The present invention also relates to a laser processing method and the like. A laser processing apparatus has an optical head provided with a laser light source part, light guide, and isolator. The optical head has an emitting optical system, irradiation optical system, and light collecting optical system. The method of measuring backward light uses a photodetector to detect, from reference light introduced from a measurement light source into the optical head, the power of an optical component that has passed through the isolator, while changing the position of the measurement light source.

Abstract: A chirped pulse amplification laser system. The system generally comprises a laser source, a pulse modification apparatus including first and second pulse modification elements separated by a separation distance, a positioning element, a measurement device, and a feedback controller. The laser source is operable to generate a laser pulse and the pulse modification apparatus operable to modify at least a portion of the laser pulse. The positioning element is operable to reposition at least a portion of the pulse modification apparatus to vary the separation distance. The measurement device is operable to measure the carrier envelope phase of the generated laser pulse and the feedback controller is operable to control the positioning element based on the measured carrier envelope phase to vary the separation distance of the pulse modification elements and control the carrier envelope phase of laser pulses generated by the laser source.

Abstract: A method for operating a frequency converted light source includes sweeping a wavelength control signal of a semiconductor laser over an initial signal range and measuring an optical power of an output beam emitted from a wavelength conversion device coupled to the semiconductor laser. The wavelength control signal of the semiconductor laser may then be swept over at least one truncated signal range and the optical power of the resulting output beam is measured. The at least one truncated signal range may be centered on a point corresponding to a maximum power of the output beam of the sweep of the wavelength control signal over the preceding signal range. An operational signal range for the wavelength control signal is determined such that a midpoint of the operational signal range corresponds to the maximum optical power of the resulting output beam of the sweep over the preceding signal range.

Abstract: Systems and methods for stabilizing laser frequency based on an isoclinic point of an atomic or molecular medium are provided herein. A system may include: a transmission cell containing a gas and configured to transmit light from the laser, the gas having an absorption spectrum with an isoclinic point; a photodiode generating an output based on an amplitude of transmitted laser light; and circuitry configured to tune the frequency of the laser to the isoclinic point of the absorption spectrum based on the output. The absorption spectrum may have first and second overlapping peaks respectively corresponding to first and second transitions of the gas, the isoclinic point being a saddle point between the first and second peaks. The first and second peaks may have substantially equal amplitude as one another and/or may broaden substantially equally as each other as a function of a physical parameter of the gas.

Abstract: An image display device including a laser light source device that includes: laser elements of different output wavelengths; a pulse signal generating unit that generates pulse signals based on a video signal; a laser driving unit that drives the laser elements in synchronization with the pulse signals; an optical combining system that combines laser beams, outputs a combined laser beam, and retrieves part of the combined laser beam; a light amount measuring unit that measures a light amount of a retrieved laser beam; and a light amount adjusting unit that causes the laser driving unit to individually adjust a light amount for the each laser element based on a measurement value, wherein the pulse signal generating unit operates in a light amount measuring mode so that emission timings would not coincide one another, and the light amount measuring unit individually measures a light amount of the each laser element.

Abstract: Apparatus and method for control of lasers (which use an array of optical gain fibers) in order to improve spectrally beam-combined (SBC) laser beam quality along the plane of the SBC fiber array via spectral-to-spatial mapping of a portion of the spectrally beam-combined laser beams, detection of optical power in each of the spatially dispersed beams and feedback control of the lasers for wavelength-drift correction. The apparatus includes a diffractive element; a source of a plurality of substantially monochromatic light beams directed from different angles to a single location on the diffractive element, wherein the diffractive element spectrally combines the plurality of light beams into a single beam. A controller adjusts characteristics of the light beams if one of the light beams has become misadjusted. In some embodiments, the controller adjusts the wavelength tuning of the respective fiber laser.

Abstract: Disclosed is a high current radiation system. The system includes a high current radiation source to generate radiation and an analog circuit to generate, based, at least in part, on an input signal representative of the present current level delivered to the high current radiation source and a user-controlled input representative of a desired current level, an output signal to control a current level to be delivered to the high current radiation source. The system further includes a current driver to control the current delivered to the high current radiation source based, at least in part, on the output signal of the analog circuit.

Abstract: A power monitoring system uses a low loss reflective element to partially split the output laser beams from an array of laser sources, in a parallel configuration, to produce a monitor beams for each laser source. Each of these monitor beams may propagate within the reflective element in a lossless manner under total internal reflection and into one of a plurality of photodiodes that sense an optical characteristic such as output beam intensity, where this sensed signal is then used as part of a feedback control to control operation of the laser sources in the array.

Abstract: This invention relates to opto-electronic systems using semiconductor lasers driven by optical phase-locked loops that control the laser's optical phase and frequency. Feedback control provides a means for precise control of optical frequency and phase, including the ability for broadband electronic tunability of optical signals and the cascading of multiple lasers for enhanced tunability and coherent combining for increased output power.

Abstract: A circuit for driving a light-emitting element such as a laser diode LD has a boost circuit for boosting an input voltage to supply it to the light-emitting element, a photoreceptor such as a photodiode PD for monitoring light from the light-emitting element; and a boost control circuit for controlling a boost voltage of the boost circuit based on a monitored amount of the photoreceptor. In the method for driving a light-emitting element by boosting an input voltage to supply the voltage to the light-emitting element, light from the light-emitting element is monitored and its monitored amount is used as a basis to control a boost voltage to the light-emitting element. A control circuit may be provided to control a driving current that passes through the light-emitting element based on the monitored amount of the photoreceptor.

Abstract: Semiconductor lasers are driven such that high output laser beams are stably obtained without a long start up time. The light outputs of a plurality of semiconductor lasers are detected by photodetectors. The semiconductor lasers are driven by automatic power control based on comparison results between the output of the photodetectors and a set value corresponding to a target light output for the semiconductor lasers. A correction pattern that corrects the set value and/or the output of the photodetectors such that the actual light output becomes uniform is generated in advance. The set value and/or the output are varied according to the correction pattern for a predetermined period of time from initiation of drive. A single correction pattern is employed in common with respect to the plurality of semiconductor lasers.

Abstract: A projection type display apparatus is provided that is safe even when a person looks directly into a laser beam. A laser operation control unit sets the output power of at least one laser source so that intensity A (mW/mm2) of the laser beam on at least one spatial light modulation element satisfies relationship of A<686×B2 when numerical aperture B on image side of an illumination optics system is set.

Abstract: A laser system according to the invention comprises pump generating means (x02, x03) for generating at least a first and a second, preferably focused, pump beam, and lasing means (x06, x07) for emitting radiation by being appropriately pumped. The lasing means (x06, x07) is disposed in a first resonator so as to receive the first pump beam in order to generate a first beam (x21) having a first frequency, and the lasing means (x06, x07) is disposed in a second resonator so as to receive the second pump beam in order to generate a second beam (x22) having a second frequency. At least one Q-switch (x08; x17, x18) is disposed in the first and the second resonator, so that the first beam and the second beam both pass a Q-switch (x08; x17, x18). The laser system (x01) has an output (x13) generated from said first beam (x21) and said second beam (x22), and at least a part of said output (x13) is fed back to a regulation system (x14), said regulation system (x14) controlling said pump generating means (x02, x03).

Abstract: A method for monitoring laser light launched into a core of a single mode fiber includes launching a portion of light directly into the cladding about the core. The cladding launched light is a known fraction of the core launched light and can be monitored by placing a detector about the cladding. Detected light including light that was launched into the cladding and has leaked through the cladding is used as a known fraction of light in the core and can be used to control the laser light source. This can be done with a straight section of single mode optical fiber and does not require bending the fiber. Advantageously, most of the core launched light remains in the core as guided light.

Abstract: An apparatus comprising a laser transmitter having a first side and a second side, a filter coupled to the first side, a detector coupled to the second side, and a temperature controller coupled to the laser transmitter and the detector. Also disclosed is an apparatus comprising at least one processor configured to implement a method comprising receiving a photocurrent of a backward light from a laser, determining a wavelength shift offset between a wavelength of the output light and a filter transmission peak, and adjusting a temperature of the laser to substantially reduce the wavelength shift and align the wavelength of the output light with the filter transmission peak.

Abstract: A fiber laser processing apparatus controls a LD drive current ILD in a power feedback control mode (FIG. 3E) such that output of a fiber laser beam FB rises substantially from zero or a value around zero to a preceding level having no substantial effect on laser processing and arrives at a desired level (PA) for the laser processing from a preceding level PB after a first time period (preceding pulse width TB) has elapsed (time point t2 of FIGS. 3A to 3F) from the start of the rising to the preceding level (time point t1 of FIGS. 3A to 3F), and this may effectively prevent occurrence of a high-peak pulse HP at the rising edge of the fiber laser beam FB (FIG. 3F).

Abstract: A method of protecting a laser against damage caused by undesired incident light in a resonator includes measuring a parameter, which is a measure for the optical power of the incident light. In more concrete terms, the optical power occurring at a resonator mirror is measured. In response to a result of the measurement, a pumping power for the laser is reduced to reduce the optical power in the resonator to a value that is uncritical for the laser.

Abstract: An optical device comprising a 1×2 optical coupler on a planar substrate and a waveguide on the planar substrate, the waveguide having a first arm and a second arm coupled to the 1×2 optical coupler. The device also comprises an optical resonator on the planar substrate, wherein the optical resonator is optically coupled to the first arm and the optical resonator is substantially athermalized.

Abstract: In an exposure device comprising a laser controller that is configured as a circuit board capable of independently being changed, and that controls the emission of laser light from a laser emitter emitting laser light on receipt of an instruction for control given from a main controller responsible for overall control of the operation of the exposure device, error control information that is obtained in advance with regard to the circuit board and controls variations of a controlling factor due to a circuit error of the circuit board is stored into a memory provided to the laser controller prior to the provision of the circuit board to the exposure device. On receipt of an instruction for control given from the main controller to cause the emission of laser light in a predetermined amount of light, the laser controller determines a condition of emission of laser light based on the error control information stored in the memory to cause the laser emitter to emit laser light under the condition of emission.

Abstract: A highly portable, high-powered infrared laser source is produced by intermittent operation of a quantum cascade laser power regulated to a predetermined operating range that permits passive cooling. The regulation process may boost battery voltage allowing the use of more compact, low-voltage batteries.

Abstract: A laser module includes a semiconductor laser, an output optical system provided on an optical output side of the semiconductor laser, a temperature detecting element that detects a temperature of the output optical system; and an output controller that calculates a drive current to set an optical output intensity of the laser module at a desired value on the basis of temperature information obtained by the temperature detecting element, and outputs the drive current to the semiconductor laser.

Abstract: A method and apparatus may comprise a seed laser, along with an amplifier laser amplifying the output of the seed laser. A bandwidth metrology module may provide a bandwidth measurement and a bandwidth error signal may be provided using a bandwidth set point. A differential timing system responsive to the error signal can selectively adjust a differential firing time between the seed laser and amplifier laser. A beam dimension and center wavelength control system may adjust a beam dimension, within the cavity of the seed laser, to select bandwidth, and may adjust center wavelength at the same time, using a plurality of beam expansion prisms and at least one other prism or other optical element in the cavity to select center wavelength.

Abstract: A method for aligning an optical package includes applying a dither waveform and an advancement waveform to a drive mechanism. The optical package includes a semiconductor laser operable to emit an output beam with a first wavelength, a wavelength conversion device operable to convert the output beam to a second wavelength, adaptive optics configured to optically couple the output beam into a waveguide portion of an input facet of the wavelength conversion device, and a drive mechanism coupled to the adaptive optics and configured to adjust a position of the output beam. The dither waveform oscillates the adaptive optics back and forth in first and second directions to oscillate the output beam on the input facet. The advancement waveform advances the adaptive optics in an adjustment direction. Rising and falling edge times of the dither waveform are greater than rising and falling edge times of the advancement waveform.

Abstract: An apparatus and method which may comprise a seed laser defining an optical cavity producing an output. An amplifier may amplify the seed laser output. A bandwidth error signal generator may provide a bandwidth error signal from measured bandwidth and a target. A bandwidth selection element, which may comprise an adjustable sized aperture external to the cavity of the seed laser may selectively alter the bandwidth of the seed laser output. A bandwidth control system may control the bandwidth control element and also selectively adjust a differential firing time between the seed laser and amplifier or another bandwidth selection actuator to cooperated (coarsely or finely) with the bandwidth selection element to control bandwidth of the laser system.

Abstract: A laser output power command determination value from a controller (17) is input to an upper limit current determination unit (32), and an upper limit current value to be decided based on the laser output power command determination value is determined. Then, a second comparator (30) compares a command current value determined from the laser output power command determination value and a laser output power command determination value measured with a power monitor (13), with an upper limit current value determined with a upper limit current determination unit (32). The second comparator (30) determines a command current value when the upper limit current value is greater than the command current value and the upper limit current value when the command current value is greater than the upper limit current value, as a reference current value, by which reference current value a current to be supplied to pumping means is configured to be controlled.

Abstract: A gas discharge laser includes a laser housing including a laser gas and an electrode-assembly for lighting a discharge in the laser gas. The electrode assembly has a first resonant frequency when the discharge is not lit and a second resonant frequency when the discharge is lit. RF power delivering circuitry of the laser includes an arrangement for determining and recording the two resonant frequencies. RF power is applied to the electrodes at the first recorded resonant frequency to facilitate lighting of the discharge, and thereafter at the second resonant frequency to light and sustain the discharge.

Abstract: The present invention discloses a laser light source for implementing pulsed oscillation of laser light, which has a laser cavity in which a laser medium for generating emitted light with supply of excitation energy is placed on a resonance path; an excitation device for continuously supplying excitation energy to the laser medium; a monitor part for monitoring a power of light extracted at a middle point of the path of the cavity from the laser medium in accordance with the supply of the excitation energy by the excitation device; a Q-switch for modulating a cavity loss of the laser cavity; and a control part for performing such control as to stabilize a peak power or an energy of laser light pulses outputted in a state in which the cavity loss of the laser cavity is set at a second predetermined loss for oscillation of high-power pulses, based on the power of the emitted light monitored by the monitor part in a state in which the cavity loss of the laser cavity is set at a first predetermined loss for non-o

Abstract: A tunable laser cavity utilizes a dispersion compensated acousto-optic tunable filter. The wavelength accuracy and stability is achieved by a wavelength locker utilizing two separate intracavity light beams without the need to use beam splitters to significantly reduce the space typically needed by a conventional wavelength locker, and provide more stable operation and easy assembly. The acoustic optical tunable filter is constructed in such a way that two transducers are bonded on the same crystal opposite to each other to create two counter propagating acoustic waves. Dispersion occurs after the collimated light diffracted by the first acoustic wave and is compensated by the second acoustic wave traveling in the opposite direction. By using different laser gain mediums, acoustic wave driving frequencies and acousto-optical crystals, this invention can be used to make tunable lasers in wide range of optical wavelengths.

Abstract: A system, apparatus, and method may provide laser beams of two or more wavelengths from diode pumped solid-state laser sources (220, 222, 224). The beam paths of these laser beams with different wavelengths, which are generated by the laser sources (220, 222, 224), may be aligned along a common optical axis 280 by an optical configuration, to treat at least one target area. Frequency-doubled laser beams, output from a plurality of diode pumped solid state laser cavities, may be passed through fold mirrors (M2, M5, M8), and combined on a common optical axis 280, using one or more combiner mirrors (M10, M11, M12), to unify the beam paths. Selected laser beams may be delivered to a target using one or more delivery systems.

Abstract: Techniques and devices for providing optical locking of optical resonators and lasers.

Abstract: Provided is a multiple distributed feedback laser device. The laser device includes an active layer, a first diffraction grating, and a second diffraction grating. The substrate includes a first distributed feedback region, a modulation region, and a second distributed feedback region. The first diffraction grating is coupled to the active layer in the first distributed feedback region. The second diffraction grating is coupled to the active layer in the second distributed feedback region. In addition, the laser device includes a first micro heater and a second micro heater. The first micro heater supplies heat to the first diffraction grating. The second micro heater supplies heat to the second diffraction grating. The first micro heater and the second micro heater are controlled independently from each other.

Abstract: Semiconductor diode lasers are phase-locked by direct current injection and combined to form a single coherent output beam. The optical power is amplified by use of fiber amplifiers. Electronically control of the optical phases of each emitter enables power efficient combining of output beams to be maintained under dynamic conditions.

Abstract: A tunable optical local oscillator is used for optical heterodyne signal detection using an electrooptic Mach-Zehnder modulator to produce a rapidly tunable optical signal from a tunable RF frequency generator. A combination of the Mach-Zehnder modulator and optical fibers for providing stimulated Brillouin scattering are used to suppress unwanted signals for providing a spectrally pure optical local oscillator waveform. Suppression of unwanted optical signals, up to 50 dB, generated by the Mach-Zehnder modulator is obtained, resulting in high spectral purity of the optical local oscillator waveform with an extended tuning range of the tunable optical oscillator equal to the operating bandwidth of up to 60 GHz of the Mach-Zehnder modulators.