150 results about "Picosecond pulse" patented technology

The present invention relates to the apparatus, system and method for dicing of semiconductor wafers using an ultrafast laser pulse of femtosecond and picosecond pulse widths directly from the ultrafast laser oscillator without an amplifier. Thin and ultrathin simiconductor wafers below 250 micrometer thickness, are diced using diode pumped, solid state mode locked ultrafast laser pulses from oscillator without amplification. The invention disclosed has means to avoid/reduce the cumulative heating effect and to avoid machine quality degrading in multi shot ablation. Also the disclosed invention provides means to change the polarization state of the laser beam to reduce the focused spot size, and improve the machining efficiency and quality. The disclosed invention provides a cost effective and stable system for high volume manufacturing applications. An ultrafast laser oscillator can be a called as femtosecond laser oscillator or a picosecond laser oscillator depending on the pulse width of the laser beam generated.

Various embodiments may be used for laser-based modification of target material of a workpiece while advantageously achieving improvements in processing throughput and/or quality. Embodiments of a method of processing may include focusing and directing laser pulses to a region of the workpiece at a pulse repetition rate sufficiently high so that material is efficiently removed from the region and a quantity of unwanted material within the region, proximate to the region, or both is reduced relative to a quantity obtainable at a lower repetition rate. In at least one embodiment, an ultrashort pulse laser system may include at least one of a fiber amplifier or fiber laser. Various embodiments are suitable for at least one of dicing, cutting, scribing, and forming features on or within a semiconductor substrate. Workpiece materials may also include metals, inorganic or organic dielectrics, or any material to be micromachined with femtosecond and/or picosecond pulses, and in some embodiments with pulse widths up to a few nanoseconds.

A laser system capable of efficient production of high energy sub-nanosecond pulses in the 2-15 μm spectral region is disclosed. Diode pumped solid state lasers are used as pump sources. The system design is simple, reliable and compact allowing for easy integration. The laser system includes a combination of compact solid-state ˜1 micron laser sources, producing high power picosecond pulses, with optical parametric amplification and a quasi-continuous wave laser for seeding the amplification process that enables the efficient conversion of the high power ˜1 micron laser radiation to tuneable mid-infrared sub-ns pulses. New parametric processes are presented for achieving high gains in bulk nonlinear crystals. Furthermore, a method of exceeding the fundamental conversion efficiency limit of direct three wave mixing is presented. The compact and robust nature of this novel laser system opens up the use of high power and high peak power mid-infrared laser pulses to a wide variety of important medical and dental applications.

A directly diode-pumped amplifier system is disclosed which produces sub-picosecond pulses with an output power of 2 watts or more. Computer resources are coupled to the amplifier system and are configured to provide control of operating parameters of the amplifier system. An optional second harmonic generator is supplied to increase the contrast ratio and reduce the minimum focal spot size. This amplifier system can be utilized for material processing applications.

A linear optical sampling apparatus, temporally samples a modulated optical signal using the amplitude of the interference of its electric field with the electric field of a laser pulse. The apparatus includes a 90° optical hybrid that combines the optical signal and laser pulse in order to generate two quadratures interference samples S_A and S_B. A processor compensates for optical and electrical signal handling imperfections in the hybrid, balanced detectors, and A/D converters used in the optical sampling apparatus. The processor numerically scales the two quadratures interference samples S_A and S_B over a large collection of samples by imposing that the average <S_A>=<S_B>=0 and <S_A²>=<S_B²> and then minimizes 2<S_A·S_B>/(<S_A²>+<S_B²>)=cos(φ_B−φ_A)). This is done by adjusting the phase between the two quadratures (ideally either −π/2 or +π/2) so that cos(φ_B−φ_A)) is zero. The processor then generates a demodulated sample signal using the quadratures interference samples S_A and S_B. According to one feature, the hybrid sets the relative phase between two quadratures of their interferometric component so that the phase sensitivity inherent to linear optics is removed. A variety of hybrid arrangements is disclosed that can be implemented using integrated waveguide technology. The apparatus enables sampling of picosecond pulses up to 640 Gb/s with high sensitivity and temporal resolution.

The invention provides a resonant cavity for outputting mode-locking picosecond laser and a mode-locking picosecond laser device. The mode-locking picosecond laser device comprises a pumping source, a focusing lens and the resonant cavity for outputting the mode-locking picosecond laser, and the pumping source, the focusing lens and the resonant cavity are sequentially arranged along a light path. The resonant cavity is characterized that a laser crystal, a focusing device, a Fabry-Perot etalon and a semiconductor saturable absorber mirror are arranged in the resonant cavity, and the energy density of light beams acting on the semiconductor saturable absorber mirror can be sufficient to realize continuous mode-locking owing to the focusing device. Peak power of the picosecond laser device can be accurately controlled, so that different application requirements can be effectively met advantageously. Besides, pulse width of the picosecond laser device can be controlled, so that different application requirements can be effectively met advantageously. In addition, picosecond pulse width can be tuned, operation is easy, and mode-locking stability is unaffected. A pulse width tunable device is small in size and is beneficial to saving space.

A self-similarity mode locking optical fiber femtosecond laser device based on spectrum compression and amplification is composed of an optical fiber coupling output laser diode, a wavelength division multiplexing coupler, a ytterbium-mixed monomode optical fiber, an optical fiber frequency spectrum filter, a monomode optical fiber, an optical fiber collimator, a quarter-wave plate, a half-wave plate, a polarization splitting prism, a 45-degree reflector, a grating and an optical fiber isolator. Spectrum is compressed by using the self-phase modulation generated when negative chirp pulses are amplified in the ytterbium-mixed monomode optical fiber, narrow-band chirp-free picosecond pulses are formed, the optical fiber frequency spectrum filter is used for eliminating residual side lobes in nonlinear spectrum compression, self-similarity evolution is completed in the monomode optical fiber, broadband linear chirp parabola pulses are output directly, and Fourier transformation extremity femtosecond lasers are output after chirps are eliminated. The self-similarity mode locking optical fiber femtosecond laser device is high in efficiency, large in self-similarity evolution spectrum widening amount, capable of obtaining Fourier transformation extremity femtosecond laser pulses high in energy and narrow in pulse width, compact in structure and easy to operate.

Provided herein are improved methods of laser scribing photovoltaic structures to form monolithically integrated photovoltaic modules. The methods involve forming P1, P2 or P3 scribes by an ablative scribing mechanism having low melting, and in certain embodiments, substantially no melting. In certain embodiments, the methods involve generating an ablation shockwave at an interface of the film to be removed and the underlying layer. The film is then removed by mechanical shock. According to various embodiments, the ablation shockwave is generated by using a laser beam having a wavelength providing an optical penetration depth on the order of the film thickness and a minimum threshold intensity. In one embodiment, material including an absorber layer is scribed using an infrared laser source and a picosecond pulse width.

A pulsed fiber laser apparatus for outputting picosecond laser pulses can comprise a fiber delivered pulsed seed laser for providing picosecond optical seed pulses, and at least one optical fiber amplifier in optical communication with the fiber delivered pulsed seed laser. The optical fiber amplifier can comprise a gain optical fiber that receives and optically amplifies picosecond optical pulses by operating in a nonlinear regime wherein the picosecond optical pulses can be spectrally broadened by a factor of at least 8 during amplification thereof. The apparatus can further comprise a pulse compressor apparatus in optical communication with the optical fiber amplifier for providing compressed picosecond optical pulses. The pulse compressor apparatus can provide a dispersion of at least 50 ps/nm and can provide a compression ratio of the time duration of the picoseconds optical pulses received by the pulse compressor apparatus to the time duration of the compressed picosecond optical pulses of no greater than about 50.

The invention discloses a pulse-width-tunable gain-switch type picosecond pulse seed source, relating to a pulse type fiber laser device and comprising a gain-switch laser device. The pulse width-tunable gain-switch type picosecond pulse seed source is specially characterized in that the gain-switch laser device is connected with a chirp compensation module used for tuning the pulse width at a special position of a signal output by the gain-switch laser device. Further, the gain-switch laser device and the chirp compensation module are connected by a polarization maintaining fiber. Compared with the prior art, due to the arrangement of the gain-switch laser device and the chirp compensation module, the gain-switch type pulse source is internationally used for the first time in the wave band of 1030-1070 nm to generate picosecond pulses; the pulse repetition frequency can be tuned flexibly in the range of 10k-100MHz, the pulse width of basic laser is tunable in the range of 50-500ps; moreover, after the adoption of the polarization maintaining fiber, all the output seed lasers are linear polarization single-longitudinal-mode lasers or multi-longitudinal-mode lasers and are easy for industrial processing and scientific research.

The invention provides a picosecond balance pulse signal generator. The picosecond balance pulse signal generator comprises a pulse signal generation circuit, a first shaping circuit and a second shaping circuit. The pulse signal generation circuit comprises an avalanche triode pulse generation circuit which is formed by two cascaded avalanche triodes and used for generating a bipolar nanosecond balance pulse signal by an inputted negative polarity trigger pulse signal via triggering. The front end of the first shaping circuit is electrically connected with the pulse signal generation circuit and used for shaping the nanosecond balance pulse signal so that a picosecond pulse signal is generated. The front end of the second shaping circuit is electrically connected with the first shaping circuit and used for shaping trailing and overshoot of the picosecond pulse signal. The high-amplitude picosecond balance pulse signal generator is simple in structure and small and exquisite in circuit structure, and the generated balance pulse waveform is great in symmetry, small in trailing and high in amplitude so that the picosecond balance pulse signal generator can be applied to a pulse type ultra wide band radar system, and detection requirements of the pulse type radar system for different depth and resolution can be met.

The invention discloses a frequency-doubling green light laser, and relates to an optical fiber laser. The frequency-doubling green light laser comprises a pump source, an optical fiber amplifier and a frequency-doubling system, and is characterized in that: the pump source is a gain-switched picosecond pulse seed source, and the gain-switched picosecond pulse seed source comprises a gain-switched laser connected with a polarization maintaining optical fiber, an optical fiber coupler, a single longitudinal mode locking device and a chirp compensation module, wherein the output end of the gain-switched laser is connected with the single longitudinal mode locking device and the chirp compensation module through the optical fiber coupler respectively. The gain-switched picosecond pulse seed source is adopted, and seed light generated by the gain-switched picosecond pulse seed source is adjustable in repetition frequency and pulse width, is at a picosecond level and is single-mode single-frequency polarized light; after laser is amplified and frequency-doubled, the characteristics of the laser are consistent with those of the seed light, the power of the laser can reach 60w, and light-light conversion efficiency can reach 80 percent; and the whole laser is an all-fiber structure, has a simple and compact structure, and is suitable for industrial production, a complex optical alignment device and water cooling are not required.

The invention discloses a gain narrowing controlled all-fiber laser amplifier for high-power picosecond pulses. The laser amplifier comprises an all-fiber picosecond seed resource. An optical fiber amplifier is connected to an output end of the all-fiber picosecond seed resource, and an output module is connected to an output end of the optical fiber amplifier; the all-fiber picosecond seed resource is a mode-locked laser in an all-fiber ring cavity structure and comprises a pump laser, a wavelength division multiplexer, a gain optical fiber, an output coupler, a first polarization controller, a polarization beam splitter, a second polarization controller and a polarization independent isolator; and a polarization-maintaining output end of the polarization beam splitter serves as an output end of the all-fiber picosecond seed resource, a non polarization-maintaining output end of the polarization beam splitter is connected with an input end of the polarization independent isolator, the second polarization controller is fixed on an optical fiber between the polarization beam splitter and the polarization independent isolator, and an output end of the polarization independent isolator is connected with the other input end of the wavelength division multiplexer, accordingly, an all-fiber ring structure is formed. By means of the gain narrowing controlled all-fiber laser amplifier for high-power picosecond pulses, long-term stable high-power picosecond pulse laser is obtained easily, and the manufacture cost of a high-power optical fiber laser system can be reduced.

The invention relates to a feedback type high-peak-power picosecond-pulse fiber laser system. A pulse shaping unit is added to the rear of a seed source to shape pulses, the pulse width of the seed source is compressed, the waveform of the seed source is improved, and the quality of seed light is improved. A fiber isolator and a narrow-band filter are connected to the front of a pre-amplifier stage and the front of a main amplifier stage respectively, harmful ASE is filtered out, and the stability of the system is improved. A red light indicator is added between the pre-amplifier stage and the main amplifier stage, and thus the safety and the flexibility of operation on a laser are improved. Photodiodes are connected to the rear of the seed source and the rear of the main amplifier stage respectively, and real-time protection and dynamic power regulation of the laser are achieved through a master control unit. The feedback type high-peak-power picosecond-pulse fiber laser system is an all-fiber system, and thus the mechanical stability and the adaptability to the environment of the system can be effectively improved. The quality of light beams of the laser is improved through a fiber grating, the narrow-band filter and a pattern adapter, the nonlinear effect in a doped fiber is effectively suppressed, and high-peak-power picosecond-pulse laser output is achieved.

The invention discloses a nonlinear fiber and an ultrashort pulse generating device applying the nonlinear fiber, relating to a special fiber and the application field of the special fiber. The nonlinear fiber comprises an external cladding layer, an internal cladding layer and an optical fiber core region, wherein the internal cladding layer is arranged in the external cladding layer; the optical fiber core region is formed by the hollow part in the internal cladding layer; the optical fiber core region is filled with nonlinear gas which is inert gas; and both ends of the optical fiber core region are respectively provided with a packaging window for sealing. The ultrashort pulse generating device comprises a picosecond pulse source, a focusing subsystem, an optical fiber and a dispersion compensating subsystem which are sequentially connected, wherein the optical fiber is the nonlinear optical fiber. The device can increase the anti-damage threshold of the optical fiber so as to increase the optical power density of the maximum unit area of incident light signals and improve the efficiency of optical nonlinear effect and the coupling efficiency, therefore, the optical fiber with low process complexity level and relatively low cost obtains the same or more superior performances.

The invention relates to an integrated ultrashort pulse laser system with a fiber-optic seed and an integrated ultrashort pulse laser multiplier system with a fiber-optic seed. The integrated ultrashort pulse laser system comprises an all-fiber ultrashort pulse oscillator and a seed light amplifier module; the all-fiber ultrashort pulse oscillator is a fiber coupling semiconductor pumped laser used for outputting seed light which is picosecond pulse or femtosecond pulse; the seed light amplifier module comprises an optical device and is used for processing the seed light and providing satisfactory output light; the all-fiber ultrashort pulse oscillator is connected with the seed light amplifier module through an optical fiber; connectors include a fiber collimator and an isolator. The integrated ultrashort pulse laser system has the advantages of high stability, high power, no maintenance, small size and integration. The integrated ultrashort pulse laser multiplier system with the fiber-optic seed comprises the integrated ultrashort pulse laser system with the fiber-optic seed and a frequency multiplier.

The invention relates to the technical field of photoelectricity, and provides a high-power nanosecond and picosecond pulse fiber laser system. The high-power nanosecond and picosecond pulse fiber laser system comprises a control circuit system, a drive system, a feedback system, a seed source, an acousto-optic modulator, a pre-amplifier stage, a primary amplifier stage, a pulse signal optical monitor and a power monitor, wherein the control circuit system is connected with the drive system and the feedback system respectively; the seed source, the acousto-optic modulator, the pre-amplifier stage and the primary amplifier stage are connected with the drive system and are controlled by the drive system; the pulse signal optical monitor and the power monitor are connected with the feedback system and transmit signals to the feedback system; the drive system drives the seed source to become pulse signal laser lights through the acousto-optic modulator; a small amount of pulse signal laser lights are transmitted to the pulse signal optical monitor; a large amount of pulse signal laser lights are transmitted to the primary amplifier stage through an optical isolator and the pre-amplifier stage and are output from the optical isolator; meanwhile, a small amount of lights are transmitted to the power monitor; the pulse signal optical monitor and the power monitor transmit the collected signals to the feedback system; and the collected signals are fed back to the control circuit system by the feedback system. Therefore, the technical problems of high-power nanosecond and picosecond pulses are solved; and good effects of high transmission rate and stable signal are achieved.

The invention provides a lithium ion battery, a laser manufacturing method thereof and a laser washing device. Coatings at the specific surface positions of battery pole pieces can be eliminated efficiently, environmentally and stably at high quality, so that the manufacturing technology of the lithium ion battery is simplified, and the manufacturing efficiency is improved. The laser manufacturingmethod comprises the following steps: carrying out die cutting to manufacture a first battery pole piece with a lug; manufacturing a lithium iron phosphate coating with a first thickness on an aluminum foil base body; determining an area to be washed of the aluminum foil base body, and adopting picosecond pulse lasers to scan the lithium iron phosphate coating in the area to be washed in a linearlight spot manner, so that expansion and gasification occur on the lithium iron phosphate coating, the lithium iron phosphate coating is separated from the aluminum foil base body, and an area to bewelded separated from the lithium iron phosphate coating is formed; welding a pole piece in the area to be welded so as to form a second battery pole piece; and combining and connecting the first battery pole piece and the second battery pole piece so as to form the lithium ion battery.

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 picosecond pulse optical fibre laser which comprises a main cavity resonator and an outer cavity feedback part. A semiconductor laser is adopted as a pumping source; a dichroic mirror and double envelope optical fibre mixing with ytterbium form the main cavity resonator which is coupled to an outer cavity through a collimating lens; a acoustooptic modulator AOM in the outer cavity adopts Raman-Nath diffraction; and a blazed grating outputs zero-level diffraction light generated by a signal light and feeds back any level light in high-level light to the cavity resonator. The invention has simple structure and high cost performance, can realize wide-tune, narrow-line-width and stable picosecond pulse laser output and can be widely applied to the fields of laser processing, laser medical treatment, laser marking, seed light source, etc.

The invention aims to provide a picosecond narrow-pulse signal source with high output voltage, high repetition frequency and adjustable output voltage for an impulse pulse radiating antenna, and the picosecond narrow-pulse signal source is simple in structure and stable and reliable in operation. According to the technical scheme adopted to achieve the purposes, a picosecond pulse generator provided with an avalanche transistor and a Marx circuit and based on micro-strip transmission comprises circuit units T1-Tn, a DC power source, a trigger signal generation and control module and a stepping motor, wherein a contact x is fixed on a rotating shaft of the stepping motor; contacts 1-(n-1) are distributed on the periphery of the rotating shaft of the stepping motor; when the rotating shaft of the stepping motor rotates, the contact x is driven to rotate and is sequentially contacted with all the contacts 1-(n-1).