64 results about "Femtosecond fiber laser" patented technology

A modelocked fiber laser is designed to have strong pulse-shaping based on spectral filtering of a highly-chirped pulse in the laser cavity. The laser generates femtosecond pulses without a dispersive delay line or anomalous dispersion in the cavity.

A photonic-crystal fiber provides dispersion compensation in a soliton fiber laser. The anomalous dispersion provided by the photonic-crystal fiber permits construction of a femtosecond fiber laser at 1 μm wavelength without prisms or diffraction gratings. The laser produces ˜100-fs pulses with 1 nJ energy, and is a major step toward environmentally-stable all-fiber devices at 1 μm.

A fiber Chirped Pulse Amplification (CPA) laser system includes a fiber mode-locking oscillator for generating a laser and stretching into a few hundreds ps-10 ns pulse by a fiber stretcher for projecting into an acoustic-optic (AO) functioning as a pulse picker for generated a modulated laser with a reduced repetition rate for projecting to a multiple stage amplifier. The multiple stage amplifier further includes a first high-energy amplifier implemented with a large mode area (LMA) fiber for amplifying the modulated laser up to a uJ level laser and a second amplifier implemented with a PCF based Yb doped fiber to further amplify the uJ level laser to a mJ level laser.

The invention discloses a high-power femtosecond fiber laser device, which comprises a circuit and a light path, wherein the circuit comprises a circuit board, an acousto-optic modulation driver and a plurality of semiconductor diodes as pumps; the light path comprises an oscillator, a first coupler, a first-stage preamplifier, an acousto-optic modulator, a second coupler, a second-stage preamplifier, a separated pulse amplifier, a first pulse compressor, a main amplifier and a second pulse compressor; and the devices of the light path are sequentially connected with one another along the light path. The high-power femtosecond fiber laser device has irreplaceable advantages in the aspects of high-precision laser cutting, high-precision laser deep welding, special material surface treatment and the like; and the specific application comprises sapphire and toughened glass cutting, cardiovascular stent construction, high-precision machining of a thin-film solar cell and the like.

A remote all-optical synchronous optical parameter chirped pulse amplification laser system comprises a 1550nm femtosecond fiber laser, a fiber coupler, a transmission fiber and a fiber connector, a fiber frequency converter, a regenerative amplifier, a frequency-doubling crystal, a fiber stretcher, a optical parameter amplifier and a compressor. The invention is characterized in that signal light and pump light source come from the same fiber laser, leading to the great stability, and the fiber transmission in the system is used for replacing the transmission in the air, realizing the control on the remote laser transmission and remote optical parameter chirped pulse amplification, ensuring the synchronization of the high precisions of signal light pulses and pump light pulses of sub-10 femtosecond magnitude and achieving the high-precision control on luminous beam structure. The invention has the advantages of stable system, simple structure, great flexibility, and easy application and integration with a remote OPCPA amplification system.

The invention relates to a terahertz spectroscopy test apparatus and system. A femtosecond fiber laser is used for generating pump light and probe light, the pump light excites a terahertz emission device and radiates terahertz waves, the generated terahertz waves are emitted to a sample suspension device to radiate a to-be-tested sample arranged in a suspension manner, and the probe light is directly sent to a terahertz detecting device. The terahertz detecting device receives the terahertz waves emitted after passing through the sample suspension device, and the terahertz waves and the probelight are together sent to a signal processing circuit to obtain corresponding terahertz time domain spectrums. Through the above terahertz spectroscopy test apparatus and system, the to-be-tested sample does not need to be fixed with instruments such as clamps, and the condition that during terahertz spectroscopy testing, the terahertz waves are radiated to the instrument for fixing the to-be-tested sample, and the testing results are affected is avoided; and compared with a conventional terahertz spectroscopy test device, the terahertz spectroscopy test apparatus has the advantage of beinghigh in test result accuracy.

The invention discloses a single-fiber-type CARS excitation source device and realization method based on two-stage non-linear tuning. The device comprises a femtosecond fiber laser light source, an electric control light power attenuator, a first-stage tuner, a pulse broadening device, a second-stage tuner, a pump laser, a wavelength division multiplexer, a gain fiber, an optical filter and an output port. The femtosecond fiber laser light source outputs femtosecond pulses serving as Stokes optical pulses which enter the electric control light power attenuator; power control optical pulse wavelength tuning is realized in the first-stage tuner; the pulses are broadened to be femtosecond pulses through the pulse broadening device, and the femtosecond pulses then enter the gain fiber for amplification; signal optical pulses and idler frequency optical pulses are generated in the second-stage tuner, wherein the signal optical pulses serve as pump optical pulses of a CARS source; the optical filter filters the idler frequency optical pulses and the residual pump continuous light; and the rest optical pulses are output from the output port. Compared with the prior art, the device adopts a single-fiber light path structure and electric control tuning, and has the advantages of compact structure, anti-interference, high reliability and fast tuning speed; and CARS rapid imaging requirement is met.

The invention discloses a robot and method for cleaning external glass in a room based on femtosecond laser. The robot comprises a femtosecond fiber laser, a real-time monitoring system and a control center, wherein both the femtosecond fiber laser and the real-time monitoring center are connected with the control center; the femtosecond fiber laser is used for removing dust and stains from the surface of the glass; the real-time monitoring system comprises a positioning instrument, a glass thickness detection instrument, a glass layer detection instrument and a glass light transmittance detection instrument; the positioning instrument is used for positioning dust and stains on the glass. Dust on the outer surface of a glass curtain wall or a glass window can be removed under the situation that the robot is arranged in the room, so that danger of outdoor cleaning is avoided, rapidness and high efficiency are realized, and the problems of high danger and high operation difficulty of the conventional outdoor cleaning robot, short service life caused by long-time outdoor exposure, and the like are solved.

The invention belongs to the technical field of material morphology characterization, and particularly relates to a device and a method capable of performing three-dimensional imaging on a solid material. The device comprises a light source system, a light splitting element, a two-dimensional translation stage, a first reflector, a spectrograph and a signal processing system, the light source system comprises a femtosecond fiber laser, and the repetition frequency and the offset frequency of the femtosecond fiber laser are locked to an atomic clock to form an optical frequency comb; after a light beam emitted by the light source system is divided into two beams by the light splitting element, one beam is used as a reference light beam and vertically enters the first reflector; one beam isused as a detection light beam to be incident to the surface of a to-be-detected sample placed on the two-dimensional platform; the reference light beam and the detection light beam are respectively reflected and then returned to the light splitting element, the reference light beam and the detection light beam coincide at the light splitting element and interfere, and interference signals enter the spectrograph and then are calculated by the signal processing system to obtain the three-dimensional morphology of the to-be-detected sample. The three-dimensional morphology imaging of the sampleto be detected is realized, the measurement precision is high, and the device can be widely applied to the field of materials.

The invention belongs to the technical field of optical communication, and particularly provides a femtosecond fiber laser device high-precision pulse POD control method and circuit. The femtosecond fiber laser device high-precision pulse POD control circuit comprises a sequential circuit, a seed clock circuit and an AOM drive circuit, wherein the seed clock circuit is connected with the sequential circuit, the AOM drive circuit is connected with the sequential circuit, the seed clock circuit is used for converting seed laser pulse into a clock signal and transmitting the clock signal to the sequential circuit, the sequential circuit is used for outputting a modulation pulse signal to the AOM drive circuit according to the seed clock signal and a received external trigger signal, and the AOM drive circuit is used for screening laser pulses emitted by a femtosecond fiber laser device according to the modulation pulse signal. According to the invention, a POD control circuit is designedin a femtosecond fiber laser device, so that synchronization between output laser and an external trigger signal is ensured; and by means of excellent low-jitter and high-precision triggering performance, the femtosecond fiber laser device can be used in cooperation with an advanced scanning galvanometer and a motion platform synchronously at a high speed, so that the machining effect and efficiency are greatly improved.

The invention discloses a THz high-repetition frequency and high-power femtosecond fiber laser based on dispersive waves. The laser comprises an Erbium-doped fiber laser seed source, a frequency enhancement part, an amplification part and a pulse width compression part, wherein the output end of the Erbium-doped fiber laser seed source is connected with the frequency enhancement part via a high non-linear fiber, the output end of the frequency enhancement part is connected with the amplification part, the amplification part comprise a pre-amplification part and a two-stage main amplification part, and the output end of the amplification part is connected with the pulse width compression part; a laser signal generated by the Erbium-doped fiber laser seed source is subjected to non-linear frequency conversion of the high non-linear fiber, and the frequency of the laser signal is enhanced to THz high repetition frequency via the frequency enhancement part, the frequency of the laser signal of the THz high repetition frequency is amplified via the pre-amplification part and the two-stage main amplification part of the amplification part, and the laser signal is further processed by thepulse width compression part to output a high-power femtosecond pulse signal of the THz high repetition frequency. The laser provided by the invention is simple in installation structure, prone to implement, low in cost and convenient to popularize.

The invention relates to a mode-locked state detecting device for a femto second fiber laser. The middle of the left inner wall of a casing is provided with a fiber collimator, a first bandpass filter plate is arranged in the light emergent direction in the bottom of the casing, a second bandpass filter plate is arranged in the left light emergent direction of the first bandpass filter plate, the middle portion of the right inner wall of the casing is provided with a photoelectric detector, the photoelectric detector is electrically connected with a voltage monitoring unit, and the top of the casing is provided with a casing cover. The device can solve the problem that the fiber laser which is characterized by short pulse, high spectral width and high repetition frequency in the precise instrument measuring field cannot determine the mode-locked state when the fiber laser needs to be started automatically, and ensures that the femto second laser can determine the mode-locked state in the operation stage; a corresponding detecting method is simple in operation, and high in determining accuracy, reliability and applicability; and the device and method are suitable for determining the mode-locked state of the femto second laser which is widely applied to the precise measuring field.

The invention discloses an ultra-short pulse fiber laser system using a graphene saturable absorber to lock a mode. The ultra-short pulse fiber laser system comprises a ring fiber laser seed source and a chirped amplifier, wherein the ring fiber laser seed source comprises the graphene saturable absorber, a wavelength division multiplexer, a Yb doped active fiber, a first passive fiber, an output coupler, a band-pass filter, an optical isolator and a second passive fiber; the chirped amplifier comprises a first-stage stretcher, a first-stage amplifier and a negative dispersion element; and the first-stage amplifier is composed of an active fiber, a beam combiner and a pumping source. The ring fiber laser seed source provided by the invention can output linearly chirped pulses, and these linearly chirped pulses can be amplified and de-chirped under the amplification of the chirped amplifier and the compensation action of the negative dispersion element, so as to obtain femtosecond pulses, and a Yb doped femtosecond fiber laser can be realized. The ultra-short pulse fiber laser system using the graphene saturable absorber to lock the mode provided by the invention fills the technical gap of the Yb doped femtosecond fiber laser.

The invention discloses a pulse energy improving method of a self-starting Figurase-9 passive mode-locked fiber laser. The pulse energy improving method is applied to the Figurase-9 fiber laser composed of an equivalent NALM annular cavity, a linear arm, a rotating motor and a pumping source. The method comprises the following steps: 1, obtaining the linear phase shift amount of a nonreciprocal phase shifter; 2, obtaining the splitting ratio of the equivalent NALM annular cavity; and 3, setting the output power of the pumping source and the parameters of the nonreciprocal phase shifter, and performing circulating until the output pulse energy of the Figure-9 fiber laser (1) is improved. According to the invention, higher nonlinear phase shift tolerance during single-pulse mode-locking operation of the Figure-9 fiber laser with the self-starting function can be realized, so that the output monopulse energy is greatly improved, the self-starting low-noise large-energy femtosecond fiber laser capable of stably operating for a long time is obtained, and the laser has a wider application prospect in the field of femtosecond laser pulses.

The invention provides a low repetition frequency erbium-doped femtosecond fiber laser, which comprises an NALM ring, a main ring and a first coupler, and is characterized in that the NALM ring comprises a pumping source input end, a wavelength division multiplexer, a polarization-maintaining erbium-doped fiber and a first polarization-maintaining passive fiber, and the first polarization-maintaining passive fiber is an annular main body of the NALM ring; the pumping source input end, the wavelength division multiplexer and the polarization-maintaining erbium-doped optical fiber are all connected to the first polarization-maintaining passive optical fiber; the main ring comprises a polarization-maintaining isolator, a second coupler, an output end and a second polarization-maintaining passive optical fiber, the second polarization-maintaining passive optical fiber is an annular main body of the main ring, the polarization-maintaining isolator and the second coupler are connected to thesecond polarization-maintaining passive optical fiber, and the output end is connected with the output end of the second coupler; and the first coupler connects the NALM ring and the main ring. According to the laser, the NALM ring is fully utilized for mode locking, the repetition frequency is reduced, the stability is high, the structure is simple, and the cost is reduced.

The invention belongs to the technical field of femtosecond laser application, and particularly provides intelligent system and method for destroying targets by utilizing femtosecond laser. An artificial intelligence module controls the energy of a femtosecond fiber laser and cooperated linkage of a motion platform, so that a target is automatically repaired or destroyed; and a camera and a zoom lens scan the target in real time, the information of the target is fed back to the artificial intelligence module in real time during the target repairing or destroying process, and whether one area on the target is a processing object or not is judged through the artificial intelligence module, so that the switching between the scanning state and the processing state is realized through adjustingthe energy of the femtosecond fiber laser, and the aim of accurately repairing and destroying the target through femtosecond laser is achieved. The device is small in size, high in intelligent level,and wide in application prospect.

The femto second laser features that the pumping light is coupled to enter into the transmission optical fiber and optical fiber beam splitter, and the then enter into toroidal cavity optical fiber laser comprising connected Er doped optical fiber and laser optical fiber. The toroidal cavity is provided with polarized optical fiber isolator, optical fiber polarization controller and optical fiber output coupler, and in the laser output terminal there is multiple-port output power optical fiber splitter. The present invention solves the problem of optical fiber splitting coupling, raises laser transmission quality and coupling efficiency, provides optical fiber laser with multiple port output in required slitting coupling ratio and makes laser application more convenient and flexible.

A terahertz radiation source is described which includes a pulsed femtosecond fiber laser, a pulse shaper, an optical amplifier and a nonlinear crystal, wherein the laser, pulse shaper, optical amplifier and nonlinear crystal are configured and/or situated in such a way that a laser pulse I, II, III, IV produced by the laser first passes through the pulse shaper, then the optical amplifier, and then the nonlinear crystal. Also described is a related imaging and/or spectroscopy system, a method for generating terahertz radiation, a method for detecting and/or examining life forms, objects, and materials using a system of this type, and a use of a source and a system of this type.

The invention discloses an all-polarization-maintaining fiber femtosecond laser based on hybrid modulation mode locking, and belongs to the technical field of laser. The laser comprises a nonlinear amplification loop mirror, a linear arm, a first semiconductor laser, a first wavelength division multiplexer and a saturable absorber reflector. The nonlinear amplification loop mirror comprises a polarization-maintaining passive optical fiber, a first polarization-maintaining gain optical fiber and a coupler; the polarization-maintaining passive optical fiber and the first polarization-maintaining gain optical fiber are connected together through the coupler, the first output end of the coupler is connected with one end of the linear arm, and the other end of the linear arm is connected with the saturable absorber reflector; the saturable absorber reflector is used for self-starting mode locking of the laser and serves as a reflector to form a resonant cavity with the annular laser transmission structure to achieve reciprocating oscillation of laser pulses. According to the invention, the saturable absorber reflector is adopted, the mode-locked self-starting of the laser is realized, and the nonlinear amplification loop mirror and the linear arm adopt a full polarization maintaining optical fiber structure, so that the stability of the system is improved.

The invention discloses a low-threshold self-starting full-polarization-maintaining femtosecond optical fiber laser of an automatic shearing mechanism of a motor train unit cable, belongs to the technical field of cables, and aims to solve the problem that in the prior art, when the motor train unit cable is manually sheared, manual operation is relatively complex and prone to errors. The surface of the workbench is sequentially provided with the take-up and selection mechanism, the cable shearing mechanism and the cable positioning mechanism from right to left; the wire size box is mounted right above the take-up and wire selection mechanism; two cable fixing mechanisms are arranged on the left side of the cable positioning mechanism; the V-shaped groove is formed in the left side of the cable fixing mechanism; the cable winding mechanism is installed on the left side of the V-shaped groove; the upper guide rail and the lower guide rail are fixed on the side of the workbench; the rack is mounted between the upper guide rail and the lower guide rail; the cable clamping mechanism is installed on the rack, the upper guide rail and the lower guide rail; and the robot and the wire number gripper mechanism are arranged at the front end of the surface of the workbench, and the robot is installed between the wire number gripper mechanism and the take-up sub wire selection mechanism. Automation is achieved, the cost is reduced, and the production efficiency is improved.

Apparatus and methods for generating controllable, narrow-band radiation at short wavelengths, driven by two colors injected into a structured waveguide. The use of multicolor excitation with the structured waveguide allows the use of very small guided beam diameters, without damaging the waveguide. Reduced guided wave mode area combined with low intensities required to drive wave-mixing frequency conversion allow the use of very compact, high average power, moderate peak intensity femtosecond fiber laser technology to drive useful conversion efficiency of laser light into the deep-UV and vacuum-UV at MHz repetition rates.

The invention discloses an ultrahigh repetition frequency femtosecond fiber laser system applied to material micromachining. The ultrahigh repetition frequency femtosecond fiber laser system comprises a gain switch semiconductor seed source which is used for generating a GHz repetition frequency picosecond-order seed pulse, a signal light regeneration system used for generating seed pulses with high coherence degree and near conversion limit, an optical fiber pre-amplifier used for performing power pre-amplification and spectrum broadening on the picosecond seeds, a pulse selector used for generating a burst pulse string, a pulse pre-chirp device used for optimizing the amplification quality in the amplification process of the seed pulse, an optical fiber power amplifier used for improving the average power and pulse energy of the pulse, and a pulse compressor used for compensating chirp of the amplified pulse to obtain ultrashort pulse output close to the conversion limit. By the adoption of the ultrahigh repetition frequency femtosecond fiber laser system, high-power, high-beam-quality and high-stability linear polarization femtosecond pulse laser output can be achieved, the gain modulation semiconductor laser which is mature, stable, free of a saturable absorber loss device and high in reliability is adopted to replace a traditional mode-locked oscillator and a frequency superposition module, and the ultrahigh repetition frequency femtosecond fiber laser system is more suitable for being applied to the field of industrial production.

The invention provides a full polarization-maintaining femtosecond fiber laser system. The system comprises a seed source and an amplifier, and the amplifier comprises an amplification stage, a stretcher and a compressor, wherein the seed source is a mode-locked fiber laser, the mode-locked fiber laser outputs laser pulses, the laser pulses are connected with a first polarization-maintaining isolator and then are connected to a first-stage amplifier, and the pulse with the increased output power after the first-stage amplification is accessed to the stretcher through a second polarization-maintaining isolator; the stretched pulse is accessed for the second-stage amplification, and the pulse with the increased output power after the second-stage amplification is accessed to a compressor through a third polarization-maintaining isolator and is compressed through a compression-stage pulse. The full polarization-maintaining femtosecond fiber laser system has the advantages that the full polarization-maintaining femtosecond fiber laser system is composed of all-polarization-maintaining devices, the output power of the laser is improved, the shorter and higher-quality pulses are obtained; the full polarization-maintaining femtosecond fiber laser system realizes the all-fiber, is miniature and is high in stability; finally, the pulse width is compressed into 63 fs through an amplification system, and the maximum output average power is 350 mW.