200 results about "Femtosecond pulsed laser" patented technology

The invention relates to methods of writing a light-guiding structure in a bulk glass substrate. The bulk glass substrate is preferably made from a soft silica-based material having an annealing point less than about 1380°K. A pulsed laser beam is focused within the substrate while the focus is translated relative to the substrate along a scan path at a scan speed effective to induce an increase in the refractive index of the material along the scan path. Substantially no laser-induced physical damage of the material is incurred along the scan path. Various optical devices can be made using this method.

Waveguides produced in bulk glass using femtosecond pulsed lasers have diameters and refractive index profiles that are manipulated by additional motions or beams. For example, spot focuses of the femtosecond pulsed lasers trace overlapping or widened tracks by superimposing additional relative motions between the spot focuses and the bulk glass. Additional femtosecond pulsed beams can also be used to produced widened waveguides.

The invention discloses a laser combined machining and profile modification method of a micro deep borehole without a recast layer. The method of the invention includes the following steps: first, a micro deep cooling borehole of a turbine blade is roughly machined by high power laser or electric sparks, and the like; the allowance for finish of the aperture is more than the thickness of the recast layer produced by using the machining method; and femtosecond laser is used for the secondary finish machining and profile modification of the micro deep cooling borehole; while femtosecond impulse laser is used for performing the finish machining and profile modification of the primarily machined micro deep borehole, under the precondition of guaranteeing the laser energy acting with the recast layer of a workpiece is higher than the ablation threshold of the material, a light beam is inclined for certain angle according to the spiral drilling mode; and the recast layer of the internal wall of the borehole is machined to remove erosion and profile modification by combining the method of lengthening the focal depth by a long focus lens. The concept of the combined machining method and the specific machining technology are used for solving the high-efficiency and high-precision machining problems of micro deep borehole groups of turbine blades.

The invention relates to a method for improving the machining efficiency of micro-channel preparation through femtosecond laser, which belongs to the technical field of femtosecond laser application. The method includes the steps: firstly, generating the femtosecond pulse laser by the aid of a femtosecond laser system, adjusting energy by means of combination of a half wave plate and a polarizing film and modulating the femtosecond laser into femtosecond interval pulse sequence by the aid of a pulse shaper; secondly, reflecting the pulse sequence laser obtained in the first step to an objective lens for focusing through a reflector, realizing imaging by the aid of a CCD (charge coupled device) and a lighting source, moving a six-dimensional precision electric control platform and positioning a laser focus on the lower surface of a sample horizontally placed on the six-dimensional precision electric control platform; and thirdly, controlling the six-dimensional precision electric control platform to move along a laser propagation direction by the aid of a computer to machine a micro-channel on the sample. As the femtosecond laser is modulated into the femtosecond interval pulse sequence by the aid of the pulse shaper, the micro-channel preparation efficiency is improved. Moreover, introduction of a vibration source is omitted, so that controllability of precision machining cannot be reduced.

The invention relates to methods of writing a light-guiding structure in a bulk glass substrate. The bulk glass substrate is preferably made from a soft silica-based material having an annealing point less than about 1380 DEG K. A pulsed laser beam is focused within the substrate while the focus is translated relative to the substrate along a scan path at a scan speed effective to induce an increase in the refractive index of the material along the scan path. Substantially no laser-induced physical damage of the material is incurred along the scan path. Various optical devices can be made using this method.

The invention provides a light-emitting diode (LED) substrate lift-off method, which comprises the steps of: providing an LED substrate, wherein the LED substrate comprises a substrate and an epitaxial layer which is arranged on the substrate; bonding the epitaxial layer on a transfer substrate; thinning the substrate in the LED substrate by adopting a femtosecond laser system, wherein the femtosecond laser system focuses femtosecond pulse laser in the substrate, a light spot formed through focusing is a linear light spot and the length of the linear light spot is larger than or equal to the diameter of the LED substrate; and removing the remaining substrate by adopting a physicochemical polishing method to expose the epitaxial layer. The LED substrate lift-off method has the advantages that the heat produced in the lift-off process can be prevented from damaging the epitaxial layer, the rate of non-defective products is improved and the luminous efficiency is improved.

The present invention relates to the optical coherent tomographic (OCT) imaging technology. Technologically, the present invention features that longitudinal resolution of OCT is raised through either utilziing dispersive element or blocking element to change the spectrum shape of input light source or utilizing one blocking element to change the spectrum shape of reference arm returned light. The present invention may be used for the OCT system with femoto second-level laser or SLD light source. The method is simple and may be used to raise the longitudinal resolution of OCT system for 20 microsecond to 14 microsecond.

The invention relates to a multiphoton subpulse STED-SPIM (Selective Plane Illumination Microscopy) microscopic system realized by single wavelength, characterized in that the femtosecond pulse laser emitted by a femtosecond single wavelength laser is transmitted to a first splitter through a first polarization regulator to be divided into two beams of light, and a first beam of light is successively transmitted to a second polarization regulator, a second splitter, a third polarization regulator and a quarter-wave plate along a Y-axial direction to form an excitation light beam; a second beam of light is transmitted to an STED photoquenching system, and the light outputted by the STED photoquenching system is successively emitted into the second splitter, the third polarization regulator and the quarter-wave plate to be modulated into donut-shaped focus spots to form a quenching light beam; a scanner is used for scanning the excitation light beam and the quenching light beam to generate an excitation plate light source and an STED quenching plate light source; an excitation plate light source and an STED quenching plate irradiate an object to be imaged through an excitation objective lens to allow the flourescent dye of the object to be imaged to excite fluorescence, and excited fluorescence is imaged through an imaging objective lens, and is emitted to a photosensitive element or an analysis element successively through an optical filter and a convergent lens.

The invention relates to a two-tone femtosecond laser collinear pumping detecting thermal reflection system which comprises a polarization output pulse laser, a wave plate, a beam splitting element, a reflecting mirror, an electro-optical modulator, a frequency doubling crystal, an optical filter, a beam expander, an electronic control displacing platform, a cold-light mirror, a fixing adjusting frame, a focusing lens, a photoelectric detector and a filter amplifier, wherein the polarization output pulse laser is used for outputting a pulse laser; the wave plate is used for causing the laser to rotate along a polarization direction; the laser beam is divided into two mutually vertical beams along the polarization direction by the beam splitting element; the laser beam is received and reflected by the reflecting mirror; the laser beam is modulated by the electro-optical modulator; the frequency doubling crystal is used for causing the laser to generate second harmonics; the laser within an appointed wavelength interval is filtered by the optical filter; the diameter of the laser beam is expanded by the beam expander; the electronic control displacing platform can move back and forth; the laser beams with different wavelengths are combined by the cold-light mirror; a sample is fixed by the fixing adjusting frame; the laser is irradiated on the surface of the sample by the focusing lens; the photoelectric detector is used for receiving the laser passing through the optical filter and generating an electric signal; and the signal of the photoelectric detector is amplified by the filter amplifier. According to the two-tone femtosecond laser collinear pumping detecting thermal reflection system, femtosecond pulse lasers with different wavelengths are applied to pumping light and detecting light; the pumping light after being subjected to frequency doubling is filtered by the optical filter with high selective permeability; the interference of the pumping light to a detecting signal is avoided; and the accurate high-efficient measurement is realized.

The invention relates to an accessory combined type terahertz time-domain spectroscopy system. A femtosecond pulse laser device radiates linearly polarized ultra-short pulse laser, the ultra-short pulse laser passes a laser plane mirror and then passes a half-wave plate and a polarization beam splitter, and pumping light and detection light which are perpendicular to each other are obtained; the pumping light enters a terahertz emission module, and parallel terahertz waves are radiated and enter a terahertz detection module through a testing device with a sample; the detection light passes a quarter-wave plate and reaches a time delay module, the detection light is returned along the original path after being reflected by a laser retroreflection mirror, then the detection light passes the time delay module and the quarter-wave plate again, the polarization state of the detection light is converted to be consistent with that of the pumping light, the detection light is reflected by the polarization beam splitter to a foldable mirror, and then the detection light is reflected by the laser plane mirror to enter the terahertz detection module. The testing device with the sample is designed for multifunctional accessories, so functions of transmission and reflection, parallel and focusing, attenuated total reflection, reflection measurement at any angle, imaging and the like can be easily switched and used.

The invention provides a dual-color two-photon fluorescence imaging method and a device, which uses six dual-color beams for emitting along plus and minus X, plus and minus Y, plus and minus Z six directions into the sample 3, thereby forming a three-dimensional lattice for exciting fluorescence, and uses a two-dimension small hole array 6 for filtering background fluorescence in the detecting light path, uses femtosecond pulsed laser with two different kinds of frequencies for composing a dual-color beam, wherein the two are coaxial, and the wavelengths are lambada 1 and lambada 2 respectively, moreover, lambada 1 is equal to lambada 2. Two kinds of light with different wavelength form two different three-dimensional lattice structures in the sample 3, and delay line 10 is modulated for causing the six beams to have the same optical path, only in the zone where two kinds of three-dimensional lattices coincide mutually, the dual-color two-photon fluorescence can be excitated. The device provided by the invention can effectively improve resolution response and imaging speed of three-dimensional imaging, and can be conveniently operated.

The invention relates to a device for measuring time-domain waveforms of ultrafast pulses. The device comprises a microwave signal source, a femtosecond pulse laser, a light guide probe, a coaxial-to-coplanar converter, a coplanar waveguide and a lock-in amplifier, wherein the microwave signal source provides a microwave signal source for an ultrafast pulse generator and the femtosecond pulse laser, so that the ultrafast pulse generator generates the ultrafast pulses; the coaxial-to-coplanar converter transmits the received ultrafast pulses to the coplanar waveguide to generate ultrafast pulse electric fields; and time-delay lasers stimulate the light guide probe to generate photosensitive currents under the effect of the ultrafast pulse electric fields, and sampling is conducted through the lock-in amplifier. The device has the advantages that the ultrafast pulses with the pulse width of sub-10ps can be measured, the ultrafast pulses transmitted coaxially can be measured, and the ultrafast pulses transmitted in a planar manner can also be measured, so that a new breakthrough in measurement of the time-domain waveforms of the ultrafast pulses is realized, and the level of measurement of instruments, equipment and devices, which can generate the ultrafast pulses, is raised.

The invention relates to a three-dimensional real time super-resolution digital holography recording system, which belongs to the field of three-dimensional microscopic imaging technology and comprises an incident light generation system and a recording system. The incident light generation system comprises a femtosecond pulse laser, a frequency doubling crystal, a dichroscope, an optical path delay system and an unpolarized beam splitter. Said recording system comprises a microobjective and a series of polarized beam splitter and unpolarized beam splitter, a reflector, a digital camera and a computer holography image processing and reproducing system. With the technologies of wavelength division, angle division, time division and polarization division multiplexing and with the optical frequency doubling crystal, the lasers sent from the laser device can be divided into two lasers with different wavelengths to enter the recording system; then a digital holography record for the three-dimensional real time super-resolution imaging can be realized in one frame image of Charge Coupled Device (CCD) through a series of beam splitting, high resolution, large view field and large depth of field. The invention has the advantages of simple system and more information records, which can simultaneously improve the space resolution and time resolution and can be widely applied to the three-dimensional real time high-resolution imaging for the microscopic object.

The invention provides an intrinsic optical fiber Fabry-Perot temperature sensor manufactured by a femtosecond pulse laser and a manufacturing method of the temperature sensor. The intrinsic optical fiber Fabry-Perot temperature sensor manufactured by the femtosecond pulse laser comprises an optical fiber, wherein a first optical fiber inner reflector and a second optical fiber inner reflector are arranged in the optical fiber; the first optical fiber inner reflector and the second optical fiber inner reflector are formed by changing a refractive index at a fiber core along the radial direction of a single-mode optical fiber core through the femtosecond pulse laser respectively; and the distance between the first optical fiber inner reflector and the second optical fiber inner reflector is 50 to 5,000mu m. The sensor has the characteristics of severe environment resistance, high stability and low loss, is easy to multiplex with an optical fiber communication network, has a simple optical path and is easy to implement, an optical fiber to be processed is not needed to be doped or sensitized, and a formed optical fiber Fabry-Perot structure is permanent and is difficult to disappear.

The invention relates to wavelength measurement techniques, in particular to a precision laser wavelength measurement device and a precision laser wavelength measurement method. The precision laser wavelength measurement device comprises a femtosecond pulse laser, a PPLN (periodically poled lithium niobate) crystal, photonic crystal fibers, a first convex lens, a first attenuator, a first half-wave plate, a diaphragm, a second attenuator, a second half-wave plate, a first polarization beam splitter, a third half-wave plate and a second polarization beam splitter. The PPLN crystal, the photonic crystal fibers, the first convex lens, the first attenuator and the first half-wave plate are sequentially positioned on an emergent light path of the femtosecond pulse laser; the diaphragm, the second attenuator, the second half-wave plate, the first polarization beam splitter, the third half-wave plate and the second polarization beam splitter are sequentially positioned on a to-be-measured laser path. An emergent light path of the second polarization beam splitter is provided with a reflection grating, and a second convex lens, an optical filter, a third convex lens, a third attenuator and an avalanche diode detector are sequentially arranged on a reflection light path of the reflection grating; a spectrometer is connected to a signal output end of the avalanche diode detector. The precision laser wavelength measurement device and the precision laser wavelength measurement method have the advantages of simple structure, simplicity and convenience in operation, easiness in adjustment, low external disturbance, high stability and extremely high precision.

The invention discloses an improved system and an improved method for detecting the composition of a material by LIBS (Laser Induced Breakdown Spectroscopy) with high signal and noise ratio and low detection limit. The improved system combines femtosecond pre-ablation double-pulse LIBS and polarized resolution LIBS and comprises a femtosecond-pulse laser with a fixed wavelength, a super-continuum spectrum femtosecond-pulse laser, a light filter, a reflecting mirror placed by 45 degrees, a beam combining mirror, a beam expanding mirror, a telescope, a beam splitting mirror placed by 45 degrees, a polarization mirror with an adjustable polarization angle, an optical-fiber coupling mirror, an optical-fiber interface, an ICCD (Intensified Charge Coupled Device) spectrograph and a computer. The system disclosed by the invention has the advantages that double pulses are used for exciting the LIBS and light signals received are transmitted into the spectrograph by the polarization mirror, so that the detection limit of elements can be effectively reduced, the signal and noise ratio can be increased, the accuracy and the stability of detection can be improved, molecular spectrum and the atomic spectrum also can be detected simultaneously and more accurate information of the composition of the material can be provided.

The invention provides a femtosecond optical Kerr gate gated imaging device and method based on directional filtering. Light paths of the imaging device are divided into a detecting light path and a pumping light path. An object to be measured, a first convex lens, an optical Kerr gate composed of a polarizer, optical Kerr mediums and an analyzer, a second convex lens and a CCD are sequentially arranged on the detecting light path. The requirements of a 4f system are met. An optics delay line, a half wave plate and a space shaping device are sequentially arranged on the pumping light path. The imaging method includes the steps that femtosecond pulse lasers are changed into two beams through a beam splitter, and femtosecond detection pulse light passes the object to be detected and then is focused and enters the optical Kerr mediums in an incident mode; after femtosecond pumping pulse light opens the optical Kerr gate, components of information, carried in the femtosecond detection pulse light, of the object to be detected are instantly gated, finally, the components of the information reach the CCD, and a high-contrast-ratio image of the object to be detected is obtained. The femtosecond optical Kerr gate gated imaging device and method based on directional filtering have the advantages that cost is low, the light paths are simple and convenient to adjust, and optical Kerr gate gating and recognition of a characteristic structure of the object to be detected can be achieved at the same time.

Disclosed herein is a prompt gamma-ray detection apparatus for analyzing chemical materials using femtosecond pulse laser-induced neutrons, which can be effectively used in the nondestructive inspection of various materials, such as metals, coal, cement, radioactive materials and the like as well as explosives and chemical materials, and which can provide better measurement results for the analysis of basic materials, and a method of measuring prompt gamma-rays using the apparatus. The prompt gamma-ray detection apparatus is advantageous because it can non-destructively analyze the elements in a chemical sample using a femtosecond pulse laser-induced neutron generator that solves the problems of an atomic reactor for research or a radioactive isotope as a neutron radiation source.

The invention discloses a laser-assisted heating femtosecond pulse laser drilling device and method. The device includes a femtosecond pulse laser, a first beam expander, a CCD camera, a reflective plane mirror, a beam splitter, a convex lens, and a second beam expander. , a continuous laser, a femtosecond pulse laser controller, a continuous laser controller, a workpiece, a fixture, a movable workbench, a workbench controller, and a computer; meanwhile, a laser-assisted heating femtosecond pulse drilling method using the above-mentioned device is provided , the main principle is that before the femtosecond pulse laser processes the workpiece, the continuous laser is used to preheat the workpiece to be processed, and the phase change of the material does not occur during the preheating process, so as to ensure the processing advantages of the femtosecond laser and improve the quality of the material. The absorption rate of femtosecond pulse laser reduces the ablation threshold of femtosecond laser processing materials and improves the drilling efficiency of femtosecond pulse laser.

The invention discloses a method of manufacturing a surface cross-scale functional micro-nano structure; the method comprises the steps of first, scanning the surface of a base by millisecond pulsed laser to obtain a micro structural graph; scanning the manufactured micro structural graph by femtosecond pulsed laser to obtain manufacture a nano structural graph on the surface of the micro structural graph by induction. By using the method of manufacturing surface micro-nano functional structure combining millisecond pulsed laser etching and femtosecond laser induction, the cross-scale high-performance low-cost manufacture of the micro and nano functional microstructure can be achieved, the manufacturing efficiency is far higher than that of semiconductor process, and the method has a better application prospect.