576 results about "Laser amplifiers" patented technology

An apparatus generates femtosecond pulses from laser amplifiers by nonlinear frequency conversion. The implementation of nonlinear frequency-conversion allows the design of highly nonlinear amplifiers at a signal wavelength (SW), while still preserving a high-quality pulse at an approximately frequency-doubled wavelength (FDW). Nonlinear frequency-conversion also allows for limited wavelength tuning of the FDW. As an example, the output from a nonlinear fiber amplifier is frequency-converted. By controlling the polarization state in the nonlinear fiber amplifier and by operating in the soliton-supporting dispersion regime of the host glass, an efficient nonlinear pulse compression for the SW is obtained. The generated pulse width is optimized by utilizing soliton compression in the presence of the Raman-self-frequency shift in the nonlinear fiber amplifier at the SW. High-power pulses are obtained by employing fiber amplifiers with large core-diameters. The efficiency of the nonlinear fiber amplifier is optimized by using a double clad fiber (i.e., a fiber with a double-step refractive index profile) and by pumping light directly into the inner core of this fiber. Periodically poled LiNbO3 (PPLN) is used for efficient conversion of the SW to a FDW. The quality of the pulses at the FDW can further be improved by nonlinear frequency conversion of the compressed and Raman-shifted signal pulses at the SW. The use of Raman-shifting further increases the tuning range at the FDW. For applications in confocal microscopy, a special linear fiber amplifier is used.

A fiber laser amplifier system including a master oscillator that generates a signal beam. A splitter splits the signal beam into a plurality of fiber beams where a separate fiber beam is sent to a fiber amplifier for amplifying the fiber beam. A tapered fiber bundle couples all of the output ends of all of the fiber amplifiers into a combined fiber providing a combined output beam. An end cap is optically coupled to an output end of the tapered fiber bundle to expand the output beam.

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 wavelength discretely tunable semiconductor laser that addresses wide wavelength tuning range, is mode hopping free, has high output power, has fast wavelength switching time, is wavelength locking free and is relatively simple. Four exemplary embodiments disclosed herein utilize a wavelength discretely tunable semiconductor laser that comprises a discretely tunable filter and laser amplifier. In the first embodiment, the tuning element comprises a pair of cascade Fabry-Perot filters, each having a plurality of characteristic narrow transmission passbands that pass only the cavity mode under the passband. The spacing between the narrow transmission passbands are slightly different in one filter from the other filter so that only one passband from each filter can be overlapped in any given condition over the entire active element gain spectral range, thereby permitting lasing only at a single cavity mode passed by the cascade double filters. One of the two etalon filters can be made with a plurality of transmission passbands predetermined by industry, application and international standards, making this element an intra-cavity wavelength reference and eliminating further wavelength locking needs for the tunable laser. In a second embodiment, one of the two etalons is replaced by a wedge filter. The filter optical path change and thus the transmission passband shift are achieved by translating the wedge filter in a direction perpendicular to the optical axis. In a third embodiment, one of the two etalon filters is replaced by a polarization interference filter. The polarization interference filter consists of an electro-optically-tunable birefringent waveplate, a fixed birefringent waveplate, the laser cavity and T.E. polarization light emitted from the laser diode. In a fourth embodiment, the laser and wavelength tuning structure are integrated on a semiconductor substrate by epitaxy processes.

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 for 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 spectral dispersion point in a laser oscillator and an output of a laser amplifier.

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.

A fiber laser amplifier system including a beam splitter that splits a feedback beam into a plurality of fiber beams where a separate fiber beam is sent to a fiber amplifier for amplifying the fiber beam. A tapered fiber bundle couples all of the output ends of all of the fiber amplifiers into a combined fiber providing a combined output beam. An end cap is optically coupled to an output end of the tapered fiber bundle to expand the output beam. A beam sampler samples a portion of the output beam from the end cap and provides a sample beam. A single mode fiber receives the sample beam from the beam sampler and provides the feedback beam.

A laser amplifier includes a laser active slab with a source of pump power to amplify an input laser beam, the laser active slab including a block of laser active material having opposed lateral faces defining a wedge lateral dihedral angle, opposed longitudinal faces, and opposed parallel transverse faces, the wedge lateral dihedral angle specified to minimize parasitic amplified spontaneous emission. The source of pump power may be one or more laser diode bars and microlenses producing a gain sheet in the laser active slab. The lateral faces may include optical coatings highly transmitting at a wavelength of the pump power and highly reflecting at a lasing wavelength to provide a folded path for the input laser beam though the gain sheet. The laser amplifier may optionally include one or more external mirrors highly reflecting at the lasing wavelength positioned and oriented to provide one or more additional zig-zag passes through the gain sheet for the input laser beam and to provide a multi-pass-amplified laser beam.

The present invention relates to methods and systems for dynamically controlled laser amplifier configuration for composite cutting includes the steps of generating an initial wavelength-swept-with-time optical pulse in an optical pulse generator, amplifying the initial optical pulse, compressing the amplified optical pulse to a duration of less than 10 picoseconds and applying the compressed optical pulse on the composite with an ablating energy density, to controllably remove a slice of material from the composite.

A fiber laser amplifier system including a plurality of master oscillators each generating a signal beam at a different wavelength. A splitter is provided for each master oscillator that splits the signal beam into a plurality of fiber beams where a separate fiber beam is sent to a fiber amplifier. A tapered fiber bundle couples the output ends the fiber amplifiers for each wavelength group into a combined fiber providing a combined output beam, where a separate combined output beam is provided for the wavelength for each master oscillator. An end cap is optically coupled to an output end of each of the tapered fiber bundles to expand the combined output beam. A spectral beam combination grating receives the combined beams from the tapered fiber bundles at different angles and outputs an output beam of all of the combined beams as a single beam being directed in the same direction.

The present invention discloses a laser amplifier with high gain and low thermally induced optical aberrations on the amplified laser beam. The amplifier designs allow simple multipass configurations to optimally extract the gain and reduce thermally induced index of refraction aberrations, making it possible to obtain an amplified laser beam of high quality combined with very high overall gains comparable to those achievable with expensive regenerative amplifiers. The amplifier includes a thin active laser solid to create the population inversion and associated heat generation within the thin laser active solid possible for the desired gain value. The system includes a cooling device in thermal contact with the thin active laser solid to provide good heat transport and high reflectivity coatings at the wavelengths of the pump and laser wavelengths. The pump light sources are laser diodes tuned to the maximum absorption of the laser active material. The amplifier also includes an optical system to transport the pump light to the laser active solid in such a way as to further confine the absorption of light along the two orthogonal directions in the plane of the laser active solid in order to get high population inversion and consequently high gains possible.

An energy-efficient method and system for processing target material such as microstructures in a microscopic region without causing undesirable changes in electrical and/or physical characteristics of material surrounding the target material is provided. The system includes a controller for generating a processing control signal and a signal generator for generating a modulated drive waveform based on the processing control signal. The waveform has a sub-nanosecond rise time. The system also includes a gain-switched, pulsed semiconductor seed laser for generating a laser pulse train at a repetition rate. The drive waveform pumps the laser so that each pulse of the pulse train has a predetermined shape. Further, the system includes a laser amplifier for optically amplifying the pulse train to obtain an amplified pulse train without significantly changing the predetermined shape of the pulses. The amplified pulses have little distortion and have substantially the same relative temporal power distribution as the original pulse train from the laser. Each of the amplified pulses has a substantially square temporal power density distribution, a sharp rise time, a pulse duration and a fall time. The system further includes a beam delivery and focusing subsystem for delivering and focusing at least a portion of the amplified pulse train onto the target material. The rise time (less than about 1 ns) is fast enough to efficiently couple laser energy to the target material, the pulse duration (typically 2-10 ns) is sufficient to process the target material, and the fall time (a few ns) is rapid enough to prevent the undesirable changes to the material surrounding the target material.

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 CO₂ lasers for generating shorter pulses and higher peak power for the hole drilling, engraving and perforation applications.

The invention discloses a 2 mu m all-fiber coherent laser Doppler wind finding radar system, which consists of a 2 mu m off-axis Cassegrain optical antenna system, a 2 mu m laser beam splitting system, a 2 mu m seed implantation laser amplifier, a 2 mu m monitoring detector system, and a 2 mu m balanced heterodyne detection system. The system overcomes the defect of ambient interference existing in a free space optical path, overcomes the influence of shot noise on heterodyne reception signal-to-noise ratio, and solves the problems of all fiber and miniaturization of the 2 mu m all-fiber coherent laser Doppler wind finding radar system, so that the 2 mu m all-fiber coherent laser Doppler wind finding radar system has a more compact structure. In addition, the system has the characteristics of safe laser for human eye, optical path connection by adopting flexible optical fiber devices, high operability and stability, low cost, good real time, long effectively measured distance, high measurement accuracy (speed measurement and distance measurement) and the like, and has high practical value in the field of coherent laser Doppler wind finding radar.

A system for directing electromagnetic energy. The inventive system includes a first subsystem mounted on a first platform for transmitting a beam of the electromagnetic energy through a medium and a second subsystem mounted on a second platform for redirecting the beam. In accordance with the invention, the second platform is mobile relative to the first platform. In the illustrative embodiment, the beam is a high-energy laser beam. The first subsystem includes a phase conjugate mirror in optical alignment with a laser amplifier. The first subsystem further includes a beam director in optical alignment with the amplifier and a platform track sensor coupled thereto. In the illustrative embodiment, the second subsystem includes a co-aligned master oscillator, outcoupler, and target track sensor which are fixedly mounted to a stabilized platform, a beam director, and a platform track sensor. In the best mode, the stable platform is mounted for independent articulation relative to the beam director. A first alternative embodiment of the second subsystem includes first and second beam directors. The first beam director is adapted to receive the transmitted beam and the second beam director is adapted to redirect the received beam. In accordance with a second alternative embodiment, an optical fiber is provided for coupling the beam between the first platform and the second platform.

The invention provides a distributed self-adaptive optical system based on optical fibers. The distributed self-adaptive optical system based on the optical fibers comprises an emitting laser, an optical fiber beam splitter, an optical fiber phase modulator, an optical fiber laser amplifier, a photoelectric detector, a three-port optical fiber circulator, a self-adaptive optical fiber collimator and coupler array, an integrated device, a multi-channel high-voltage amplifier, a wavefront controller as well as a beacon light source, a spectroscope and a far field target. The distributed self-adaptive optical system is based on the fiber laser technology in combination with a plurality of optical fiber devices, and is characterized in that a beacon light beam is divided by use of the self-adaptive optical fiber collimator and coupler array, the wavefront error of beacon light is measured in real time and the error is decomposed to each light sub-beam in a laser array, a piston for emitting the light sub-beams and a tilting phase are controlled independently and in parallel according to the principle of phase conjugation, and the influence of atmospheric turbulence effect on the quality of the light beam at the far field target is relieved. The distributed self-adaptive optical system based on the optical fibers has important application prospects in the fields such as laser atmospheric transmission, free space laser communication and laser radar.

A laser amplification system is disclosed that enables reliable operation over large ambient temperature operating window, as well as a significant reduction of laser temperature sensitivity typically associated with diode pumped lasers. The techniques employed by the system effectively eliminate damaging gain hot spots and lower ASE and ESA thresholds, thereby increasing laser peak and average power levels. Additionally, the techniques allow for thermal programming of active gain medium material to minimize thermally induced aberrations. In one particular example embodiment, a variable dopant concentration multi-pass laser amplifier is provided having a customized active ion concentration profile, tailoring the combination of laser absorption and gain distribution using a ceramic YAG host.

A laser system including two laser amplifier modules, each comprising a solid-state laser gain material (LGM) disk, and a multi-pass optical assembly comprising a plurality of relay mirrors. The relay mirrors are grouped in two relay mirror groups. Individual relay mirrors are arranged to pass a laser beam from the first LGM disk to the second LGM disk and back to the first LGM disk, and so on. The laser beam is amplified with each pass through the LGM disk. The relay mirrors may be arranged to repeat the process of passing the laser beam to and from the two LGM disks arbitrary number of times until the desired laser beam amplification is attained. At that point, the laser beam may either released from the laser system, reflected back causing it to retrace its path through the system. This configuration increases the effective gain and improves laser power extraction.

The invention discloses an ultra-short pulse dispersion reshaping and amplitude division technology-based ultrahigh-speed optical imaging system and an ultra-short pulse dispersion reshaping and amplitude division technology-based ultrahigh-speed optical imaging method. The optical imaging system comprises a femtosecond laser oscillator, an ultra-short sub pulse string generator, a femtosecond laser amplifier, an optical beam expanding system, an afocal optical system, a wavelength amplitude division optical system and a plurality of image recording systems. The optical imaging method comprises the following steps of: outputting a femtosecond laser pulse string; changing each pulse into a group of sub pulse string; amplifying each sub pulse; performing collimation and beam expansion on the amplified sub pulse; projecting the sub pulse subjected to the collimation and beam expansion to an object to be measured; propagating the sub pulse carrying object information of different moments along different directions; and receiving and recording the sub pulse of different directions. The system and the method can realize multi-image recording of dozens of picosecond to dozens of nano seconds process of picosecond time resolution.