51results about How to "Large wavelength tuning range" patented technology

The invention discloses a distributed Bragg feedback tunable laser and a manufacturing method thereof. The method comprises the following steps: a lower waveguide layer, a multiple quantum well active area and an upper waveguide layer sequentially grow on a substrate; materials of a distributed Bragg feedback area and a phase area are obtained, wherein the band gap wavelengths of the materials of the distributed Bragg feedback area and the phase area are less than the light emitting wavelength of the laser; a grating is manufactured in the feedback area; the cladding and electrical contact layer materials grow on the whole surface of a tube core; an inverted frustum-shaped shallow ridge waveguide structure is manufactured on the cladding and the electrical contact layer of the feedback area, the phase area and a gain area, wherein the waveguide side wall of the structure is a (111) A crystal plane; electrical isolation grooves are etched in the electrical contact layer and ion implantation is carried out on the isolation grooves at the same time to realize electrical isolation between the gain area and the phase area and between the phase area and the feedback area. Through the adoption of the distributed Bragg feedback tunable laser and the manufacturing method thereof, the purpose that the feedback area has low series resistance when the concentration of implanted charge carriers is improved is achieved, and the device wavelength tuning range can be increased and the wavelength tuning sensitivity is improved.

The invention discloses a detection system of photoacoustic spectrometry gas in a fiber laser device cavity, and belongs to the technical field of optical fiber gas detection. The detection system comprises a pump light source, a wavelength division multiplexer and a computer. The annular fiber laser device cavity is jointly composed of the wavelength division multiplexer, rare earth doped fibers, an opto-isolator, a gas chamber, a tunable filter and an optical fiber coupler, wherein an input coupling mirror and an output coupling mirror are placed in the gas chamber; a quartz tuning fork is placed in the proper position in the gas chamber and is used for probing acoustic wave signals generated by laser excitation gas in the fiber laser device cavity; the signals probed by the quartz tuning fork are further exacted by a lock-in amplifier, are acquired by a data collection card and are transmitted to the computer, and after gas concentration inversion is conducted on the signals, gas concentration information is acquired. Combined with the optical fiber laser technology and the photoacoustic spectrometry gas detection technology, the detection system of the photoacoustic spectrometry gas in the fiber laser device cavity has the advantages of being high in sensitivity and cost performance, very low in cost and the like.

The invention discloses a V-shaped coupled cavity tunable semiconductor laser unit capable of directly conducting modulation at a high speed. The V-shaped coupled cavity tunable semiconductor laser unit comprises a semi-wave coupler, a wave length reference FP resonant cavity and a wave length tuning FP resonant cavity, wherein short cavity active waveguide and short cavity passive waveguide are connected in series to form the wave length reference FP resonant cavity, long cavity active waveguide and long cavity passive waveguide are connected in series to form the wave length tuning FP resonant cavity, the ratio of the optical length of the short cavity active waveguide to the optical length of the short cavity passive waveguide is equal to the ratio of the optical length of the long cavity active waveguide to the optical length of the long cavity passive waveguide, and therefore the mode jump does not occur when the laser unit directly conducts modulation at the high speed. The laser unit can further comprise a section of thin film resistor added to the top of the semi-wave coupler so that the tuning range can be enlarged, and comprise two sections of active waveguide added outside cavities and deep etching grooves so that the threshold of the laser unit can be reduced, and an optical power meter integrated on a piece is provided. According to the V-shaped coupled cavity tunable semiconductor laser unit, the C wave section and sections in a wider range can be tuned, and performance of conducting direct modulation on each communication wave with the wave length more than 10Gbps is achieved.

The invention discloses a tunable narrow linewidth external cavity semiconductor laser, comprising: a semiconductor gain chip as a laser source; An optical waveguide located on the same optical axis as the gain chip; A grating structure positioned behind the optical waveguide and positioned on the same optical axis as the gain chip and the optical waveguide; A thermistor located on one side of thegain chip and the optical waveguide centerline, avoiding the optical path, the thermistor being located close to the gain chip; An electrode attached to the optical waveguide; A heat sink, a gain chip, a thermistor, an optical waveguide and a grating structure are placed on the same heat sink; A heat sink is placed on the same semiconductor cooling sheet. The invention solves the problems of wavelength jitter and linewidth instability caused by external environment and injection current fluctuation of external cavity laser, thereby realizing accurate control of wavelength and linewidth, and realizing rapid adjustment of wavelength.

The invention discloses a multi-wavelength tunable laser based on a polarization-maintaining chirped phase-shift fiber grating, and belongs to the field of optical communication and instruments. A pumping light source (101) firstly passes through a wavelength division multiplexer (102) and enters the annular cavity structure of a laser; through gain of a doped fiber (103) with a length of 2 meters, the pumping light source passes through a polarization controller (104) and then passes through a polarization-maintaining chirped phase-shift fiber grating filter based on a piezoelectric ceramic; the polarization-maintaining chirped phase-shift fiber grating filter is composed of a polarization-maintaining chirped fiber grating (105), the piezoelectric ceramic (106) and an electric signal generator (107); signals in a bandwidth range are reflected back to a laser resonant cavity through a circulator (108) and a polarization-maintaining even fiber grating (109); and finally multi-wavelength lasers are output from a coupler (110). The multi-wavelength laser mainly is realized through that the signals generated by the polarization-maintaining even fiber grating (109) act on the polarization-maintaining chirped fiber grating (105) so as to import phase shifts. Through changing the locations and number of the imported pi phase shifts, the laser wavelengths and the number of the laser wavelengths can be tuned by the multi-wavelength laser.

The invention, which belongs to the technical field of fiber gratings, in particular relates to a liquid-clad micro-nano fiber long-period grating with the adjustable broadband. The liquid-clad micro-nano fiber long-period grating comprises a micro-nano fiber, a quartz capillary and cladding liquid. The micro-nano fiber and the cladding liquid are encapsulated in the quartz capillary; the micro-nano fiber is horizontally suspended at the center of the quartz capillary; and the space around the micro-nano fiber is filled with the cladding liquid. The micro-nano fiber is an intermediate nano-fiber portion after tapering of a single-mode fiber; and single-mode fibers are formed at the end portions of two sides extending out of the quartz capillary symmetrically after single-mode fiber tapering. A long-period grating is engraved at the middle part of the micro-nano fiber. Therefore, a problem of poor tunability of the long-period fiber grating in the prior art is solved.

The invention discloses a mid-infrared femtosecond pulse laser which comprises an ytterbium-doped fiber oscillator, a pulse stretcher, a spectrum shaping module, a crystal regenerative amplifier module, a pulse compressor, a second-order cascade nonlinear compressor module and a pulse internal difference frequency module which are arranged according to an optical path sequence. The ytterbium-doped fiber oscillator is used for generating initial laser pulses; the spectrum shaping module is used for performing spectrum shaping on the broadened laser pulse and generating a first laser pulse; the crystal regenerative amplifier module is used for amplifying the first laser pulse; the compressor module is used for carrying out nonlinear compression on the amplified and linearly compressed first laser pulse to generate a second laser pulse; the in-pulse difference frequency module is used for generating a third laser pulse of a middle infrared band from the second laser pulse through nonlinear conversion; and according to the invention, the structure of the laser is greatly simplified, the output efficiency of the pump pulse is improved, the wavelength tuning range of the mid-infrared femtosecond laser is expanded, and the cost of the mid-infrared femtosecond laser is reduced.

The invention discloses a Laguerre Gaussian optical parametric oscillator with tunable broadband topological charges. The oscillator comprises a nanosecond pulse laser, a beam shaping device, a coating cavity mirror, a periodically poled lithium niobate crystal, a temperature control device, a polarization element and a vector vortex wave plate, wherein the coating cavity mirror comprises a coating front cavity mirror and a coating rear cavity mirror which form a resonant cavity. The oscillator is advantaged in that relative positions of a vector vortex wave plate and the coating front cavitymirror meet the condition that a ratio of a concave mirror to a concave mirror is 1: 1, a self-reproduction cavity mode with smooth transition from a solid light beam to the hollow Laguerre Gaussian light beam is formed according to the imaging relation of the solid light beam and the hollow Laguerre Gaussian light beam, coupling efficiency of the cavity mode and the pump light is improved, intra-cavity loss is reduced, and finally high-efficiency, high-purity and wavelength and topological charge tunable Laguerre Gaussian light beam output is achieved.

The embodiment of the invention provides a hybrid integrated tunable outer cavity laser device and a wavelength tuning method. The laser device comprises an outer cavity and an output assembly, wherein the outer cavity comprises a reflection type semiconductor gain chip, a first collimation lens, a controlled optical grid filter, a converging lens and a semiconductor integrated chip, wherein a high-reflection film and an anti-reflection film are plated on two end faces of the reflection type semiconductor gain chip respectively; the first collimation lens, the controlled optical grid filter, the converging lens and the semiconductor integrated chip are arranged on the end face plated with the anti-reflection film of the reflection type semiconductor gain chip in sequence along a light path; a phase modulation region, a sampling optical grid region and a gain active region are integrated on the semiconductor gain chip, and are used for carrying out outer cavity phase modulation and control, cavity mode selective filtering and light power control respectively; the output assembly is arranged at a laser output side of the outer cavity and is used for outputting laser transmitted fromthe gain active region. The laser device is compact in structure, small in volume, small in coupling loss and relatively high in integration degree.

The invention relates to the field of laser array coherent combination, and discloses a coherent combination system based on a mid-infrared optical parametric amplifier. The system is composed of a phase-controllable optical parametric amplifier laser beamlet module, an active phase control module and a beam combination and photoelectric detection feedback control module; the optical parameter amplifier laser beamlet comprises three parts, namely a pumping source, a seed source and an optical parameter amplifier; and, when the power density ratio of the seed light to the pump light in the optical parametric amplifier meets a certain condition, the phases of the seed light and the output light have a determined relation, the phase of the seed light is adjusted through a phase modulator arranged in a seed source so as to lock the phase between light beams of the mid-infrared band optical parametric amplifier array, and active phase-locked coherent combination of mid-infrared light wavesis achieved. The optical parametric amplifier beamlet in the system has the advantages of high single-path output power, high conversion efficiency, high polarization degree, wide wavelength tuning range, easiness in line width control and the like.

Wavelength sweepable laser source is disclosed, wherein the laser source is a semiconductor laser source adapted for generating laser light at a lasing wavelength. The laser source comprises a substrate, a first reflector, and a second reflector. The first and second reflector together defines an optical cavity, and are arranged to support light oscillation in the optical cavity along an optical path in a direction normal to the substrate. The optical cavity comprises a void in the optical path. The second reflector is resiliently suspended by a suspension in a distance from the first reflector and having a rest position, the second reflector and suspension together defining a microelectromechanical MEMS oscillator. The MEMS oscillator has a resonance frequency and is adapted for oscillating the second reflector on either side of the rest position. The laser source further comprises electrical connections adapted for applying an electric field to the MEMS oscillator. Furthermore, a laser source system and a method of use of the laser source are disclosed

The embodiment of the invention discloses a manufacturing method of a laser and the laser. The manufacturing method comprises the following steps: sequentially dividing a first distributed feedback (DFB) region, a tuning region and a second DFB region on a substrate; respectively preparing selected area dielectric mask strip pairs on the first DFB region and the second DFB region, or preparing selected area dielectric mask strip pairs on the tuning region; sequentially epitaxially growing a lower respective limiting layer, a multi-quantum well layer and an upper respective limiting layer in a first DFB region and a tuning region which are provided with selected region dielectric mask strip pairs, and a second DFB region which is provided with selected region dielectric mask strip pairs, or in the first DFB region, the tuning region and the second DFB region which are provided with selected region dielectric mask strip pairs; the components of the multi-quantum well layer in the tuning region are respectively deviated from the components of the multi-quantum well layer in the first DFB region and the second DFB region; removing the selected area medium mask strip pairs; the laser manufactured through the manufacturing method is high in reliability, and the wavelength tuning range of the laser can be enlarged.

An improvement in a method of controlling lasing in a semiconductor laser fabricated in a photonic crystal laser having a plurality of holes into which a birefringent material with low refractive losses and low optical loses with controllable spatial refractive index orientation has been infiltrated comprises the step of rotating the molecular orientation or changing the physical orientation of the birefringent material infiltrated into the holes of the photonic crystal laser to switch cavity modes. The liquid crystal is aligned by use of an alignable photo addressable polymer layer adjacent to the liquid crystal. The cavity modes are optically switched within the laser without any requirement of external energy to maintain the lasing state of the laser, which allows its use as a memory element.

The invention discloses a terahertz source and application thereof. The terahertz source comprises a seed light source and a frequency modulation medium, wherein the seed light source generates seed light, the seed light enters the frequency modulation medium and then emits terahertz waves, the frequency modulation medium is a laser medium with Raman characteristic peaks, the frequency vout of theterahertz wave is equal to (c/[lambda]inp-c/[lambda]d)/1, [lambda]d is equal to 1/Raman characteristic peak position of the laser medium, [lambda]inp is the wavelength of the seed light, and the light speed c is 3.0*10<8> m/s. The terahertz source is small in size, few in parts, low in cost, capable of working at normal temperature and beneficial to improving application of terahertz waves in various fields, and obtains the terahertz waves based on light wave frequency conversion.