104 results about "Nonlinear absorption" patented technology

A method for machining a transparent material by the non-linear absorption of pulsed laser radiation, in the region of a laser focus, includes the following steps: a laser wavelength of between 300 and 1000 μm is selected; and laser impulses having a temporally flat beam profile are applied. The method is characterized in that the irradiation intensity is selected from an interval pre-determined for the material to be machined, in which plasma is formed without plasma luminescence. An apparatus for laser treating a transparent material includes structure to set an irradiance and inspect the treatment as being within a defined interval.

Systems and methods are provided for disrupting tissue within preretinal or retinal structures of an eye. At least one femtosecond laser pulse is directed through the cornea of the eye to a target location. The at least one femtosecond laser pulse has sufficient intensity to induce nonlinear absorption in tissue within the target location. The at least one laser pulse is corrected at an adaptive optical element as to substantially reduce dispersion and aberration of the at least one laser pulse due to changes in the wavefront profile associated with the laser pulse due to travel through eye tissue between the surface of the eye and the target location. At least the target location is imaged to produce an in vivo image of the target location. The adaptive optical element is adjusted according to distortion detected in a reflected wavefront.

The invention provides a method and a device for coaxial combined machining with tubular electrode discharging and laser irradiation, and belongs to the field of non-traditional machining and combined machining. Micro-etching machining is performed on the surface of an insulating high-hardness brittle material by virtue of a coaxial action of cone-shaped tube electrode discharging and laser irradiation, recessive material defects and stress concentration generated by pulsed laser acting on the surface of a workpiece can attract spark discharge to always act on the current area, and meanwhile, the spark discharge changes the surface shape and physico-chemical property of the current area, then nonlinear absorption of the current area on laser energy is improved, a local field enhancement effect is generated, and pulsed laser focused irradiation can accelerate an electrochemical reaction to promote generation of a stable discharge gas film layer on the surface of a hollow tool electrode; and the interactive cooperation of two types of energy achieves fixed-area micro-etching of the insulating high-hardness brittle material, the machining efficiency is significantly improved, and the machining quality is improved.

The invention discloses a glass chip packaging method. A penetrating conductive metal electrode is prefabricated in the thickness direction of a glass sheet, and laser welding packaging is carried out on a glass chip by adopting ultrafast laser light. By using an ultra-high light intensity characteristic of ultra-short pulse laser light, a nonlinear absorption effect is generated in a transparent medium and the transparent medium is melted on a focus point, so that selective micro-welding in a transparent material space is achieved. The structure size processed by the ultra-short pulse laser light can break through an optical diffraction limit and precise welding smaller than a laser wavelength is achieved. Furthermore, the interaction time of the laser light and a material is extremely short, cracks and sputtered materials, caused by different expansion coefficients, of the material can be effectively avoided; and improvement of the welding packaging precision and quality is facilitated. Compared with other packaging technologies of bonding and the like, the glass chip packaging method has the advantages that the manufacturing process is simple, the thickness of the chip is not limited, fillers of different materials do not need to be added, the strength performance, the stability and the reliability of glass chip packaging can be improved and the service life of the glass chip is prolonged.

The invention relates to a Z-scan optical nonlinear measuring device and method. The device and the method can be used for measuring the wavelengths of two lasers, wherein light sources can be continuous light or pulsed light, the pulse width and the repetition frequency are adjustable, and the incident laser power is continuously adjustable from 0 to 100%. According to the device, an optical isolator can be used for effectively eliminating the influence of surface reflection of an optical element and a to-be-measured sample to a laser so as to ensure that a measuring result is accurate and reliable; a lambda/4 wave plate is rotated to measure nonlinear optical parameters of the sample under the action of lasers in linear polarization, circular polarization and elliptical polarization states; light paths are adjusted to change the relative intensity of the two beams of light so as to implement two-tone time-resolved nonlinear absorption and refraction measurement; and the polarization states of pump light and probe light can be adjusted to measure the time response characteristics of the sample under the action of the lasers in the different polarization states. The device and the method can be used for measuring data of transmission openings, transmission closed holes and reflection openings simultaneously, thus being suitable for measurement of transparent samples and semitransparent samples.

The invention belongs to the field of war-industry high-power-laser protective materials, and particularly relates to an organic-transition-metal tin-porphyrin axial covalent functionalization multiwalled-carbon-nanotube nano-hybrided nonlinear optical function material with good nonlinear absorption performance and a preparing method thereof. According to the material and the preparing method, organic-transition-metal tin porphyrin is axially connected to the surfaces of multiwalled carbon nanotubes in a covalent bond mode through 1,3-dipole cycloaddition; due to the synergistic effect between the tin porphyrin and the multiwalled carbon nanotubes, the solubility, the dispersion stability and the nonlinear optical absorption performance of the multiwalled carbon nanotubes are improved, and the scheme is not simple physical mixing of the two different optical function materials. The prepared nonlinear optical function material has quite good solubility and quite good dispersion stability in organic polar solvents, and has quite high nonlinear optical absorption performance, and therefore the organic-inorganic nano-hybrided nonlinear optical function material shows important scientific research value and good practical application prospects.

A design of a semiconductor saturable absorber that offers a convenient and reliable way to control/decrease the recovery time of the absorption. The absorption recovery time is controlled during the epitaxial growth by using lattice-mismatched layer(s) to induce dislocations, and implicitly non-radiative recombination centers within the nonlinear absorbing region. These lattice reformation layer(s) are interposed between the distributed Bragg reflector and the nonlinear absorption region, containing quantum-wells, quantum-dots or bulk semiconductor material. The thickness and composition of the lattice reformation layer(s) is an instrumental to control the amount of non-radiative recombination centers used to trap the optically excited carriers generated in the absorption region.

The invention discloses a micro-structure mode-locking device capable of saturated absorption of nanometer materials via tapered optical fiber evanescent field effects and a manufacturing technique therefor, and belongs to the field of laser technology and nonlinear optics. The micro-structure mode-locking device is a micro-structure zone which mainly consists of a common single-mode optical fiber, a capillary glass tube, a saturable absorption nanometer material, a refractive index matching liquid, and an ultraviolet glue. In the micro-structure mode-locking device, a gel solution in which the tapered optical fiber, the refractive index matching liquid and the saturable absorption nanometer material are uniformly mixed is enclosed in a capillary glass sleeve tube; both ends are sealed viaultraviolet ray glue, and finally a micro-structure mode-locking device is formed. . The principle of the micro-structure mode-locking device and the manufacturing technique is to complete the shaping of passing beams via use of nonlinear absorption effects between an evanescent field produced by a tapered optical fiber bundle waist part and the saturable absorption nanometer material. Via the whole structure of the micro-structure mode-locking device, an all optical fiber state is realized; the micro-structure mode-locking device is advantaged by simple structure, good environmental stability and little susceptibility to external pollution; industrial application can be facilitated.

The coherent imaging device of 4f position based on the Michelson's interferometer is the third-order nonlinear refractive index used to measure the nonlinear photo medium. It can solves the problem of data treating bother, nonlinear absorption of traditional 4f coherent imaging technology and the small deform range, high request for stability and complex data treating of Mach-Zehnder interference. The first linear attenuating sheet, the first beam splitter, the second aperture diaphragm and second all-mirror are set at the central axis of the laser emitting mouth. the right side of low emitting point on first beam splitter is 45degree with the central axis of laser emitting mouth. The second linear attenuating sheet, the second convex, the first convex, the first beam splitter, the first aperture diaphragm and the first all-mirror are set at the central axis of the CCD camera image collecting side; the lower side of right emitting point on first beam splitter is 45degree with the central axis of image collecting side.

The present invention discloses a method for measuring transient state optical nonlinearity of a material. According to the method, a laser beam is divided into two laser beams such as pump light and detection light, the pump light passing through delay line is focused onto a sample to be measured to make the non-linear sample produce optical nonlinearity, the detection light passing through the sample is divided into two beams through a light splitter, one beam directly enters a first detector, and the other beam passes through a round baffle, then passes through a round small hole, and finally enters a second detector; and the method is characterized in that the round baffle is placed in the detection optical path in a far filed manner, and the measurement steps comprise: (1) placing the sample to be measured, and respectively collecting the energies of the detection light at different times by using the two detectors, and (2) processing the detection light energy curves at different delay times to obtain the optical nonlinearity parameter. According to the present invention, the measurement system working according to the method of the present invention has advantages of high sensitivity, simple data processing, concurrent nonlinear absorption and refraction measurement, no requirement of separation, and the like.

The invention discloses a laser direct writing micro-nano structure system based on single-wavelength double beams. The system comprises a pulse laser device 1, a first high-speed optical switch 2, afirst 4f lens group 3, a first spatial filtering small hole 4, a polarization beam splitter 5, a continuous laser device 6, a second high-speed optical switch 7, a second 4f lens group 8, a second spatial filtering small hole 9, a spiral phase plate 10, a quarter-wave slide 11, a first reflector 12, a first semi-reflective semi-transparent mirror 13, an objective lens 14 and a to-be-photoetched sample 15. The system is advantaged in that two beams of laser with the same wavelength are selected as an excitation light source and a suppression light source respectively, high transient light intensity of the exciting light is utilized to ensure that nonlinear absorption of the material is used for initiating photopolymerization reaction, micro-nano structure processing is realized, the phase modulation technology is combined to adjust an inhibiting light focus into a hollow shape, so polymerization reaction is further localized in the central area of the exciting light, and a purpose of compressing the polymerization size is achieved.

The invention belongs to the field of military industry strong laser protective material, and more specifically discloses organic transition metal stannum porphyrin axial functionalized reduced graphene oxide nano hybrid light-sensitive functional materials with excellent nonlinear absorption performance, and a preparation method of the organic-inorganic covalent functionalized nano materials. Development of the novel porphyrin covalent graphene nonlinear absorption materials with excellent solubility is used for solving problems that graphene is poor in solubility and dispersion stability, and conventional strong laser protective materials are limited. According to the preparation method, organic transition metal stannum porphyrin is connected with the surface of reduced graphene oxide via covalent axial bonds via 1,3-dipolar cycloaddition and free radical addition instead of simple physical mixing of two materials with different optical functions; solubility, dispersion stability, and nonlinear absorption performance of graphene are improved via synergistic effects of organic transition metal stannum porphyrin with reduced graphene oxide; nonlinear optical performance and solubility of the obtained materials are improved greatly; and application prospect is promising.

The invention discloses a pumping light and detection light coaxial non-angle pumping detection method and system used for detecting optical nonlinearity. A laser beam is divided into two beams, one beam with strong light intensity is pumping light, one beam with weak light intensity is detection light, and the pumping light is focused on a to-be-measured non-linear sample by time delay, so as tomake the non-linear sample in a basic state produce non-linear absorption; the detection light passes through a concentric baffle and then is converged on the to-be-measured non-linear sample by a lens, the emergent pumping light is blocked by a second concentric baffle, and the detection light passes through the second baffle and then enters a detector completely; the distance between the bafflein front of the lens in the detection optical path and the lens and the distance between the baffle at the rear of the lens in the detection optical path and the lens conform to a lens imaging law, and the radius of the baffle in front of the lens is larger than that of a reflecting mirror of the pumping light, and the radius of the rear baffle can block all the pumping light and makes all the detection light pass through. The pumping light and detection light coaxial measurement material transient optical nonlinear absorption kinetics is achieved without polarizing films and optical filters.

The invention discloses an adjustable saturable absorbing device, a production method of the adjustable saturable absorbing device and an application of the adjustable saturable absorbing device in a time domain output mode adjustable optical fiber pulse laser device. Multiple types of low-dimensional nano materials are deposited or transferred onto a transparent optical substrate or an optical substrate with a reflecting rate of 0.1%-99.9% and the optical substrate is arranged inside a movable or rotatable device to form the adjustable saturable absorbing device; the adjustable saturable absorbing device is applied to the optical fiber pulse laser device to achieve a method of switchover among a continuous laser output mode, a Q-switching laser output mode, a mode locking pulse output mode and the like. The adjustable saturable absorbing device can adjust the optical parameters such as linear absorption and nonlinear absorption to achieve switchover among the continuous laser output mode, the Q-switching laser output mode, the mode locking pulse output mode and the like and accordingly to provide better pulse working states; by introducing a new degree of freedom, the adjustable saturable absorbing device also provides a mode for regulating and controlling the pulse laser output working modes; the pulse laser working modes based on the adjustable saturable absorbing device is adjustable, high in stability and power and wide in working wavelength range.

The invention discloses an integrating sphere model for calibrating tissue oxygen indexes. The integrating sphere model comprises a hemispherical integrating sphere, a base, a color filter and a barrier. The hemispherical integrating sphere is supported by the base, the color filter is convenient to replace, the barrier covers the upper side of the hemispherical integrating sphere, a light hole of a light source and three light holes of receivers are formed in the barrier and are arrayed to form a straight line, the color filter comprises a group of light-transmittance films which have unequal absorptive actions on photons at wavelengths of 760nm and 840nm and nonlinear absorption lines near the wavelengths of 760nm and 840nm, and the color filter is selectively placed on one light hole of the receiver. The integrating sphere model has the advantages that the stable optical integrating sphere model is used as a calibrating medium of a blood oxygen instrument instead of a blood model and is stable and reliable in performance; the color filter is used during calibration, so that the integrating sphere model can have different attenuation actions on the photons at the different wavelengths, tissue oxygen index values measured by the blood oxygen instrument can be calibrated in a multi-point manner, and a calibration effect can be improved.

The invention provides an underwater laser shock non-die incremental forming device and method. The underwater laser shock non-die incremental forming device comprises a computer, a laser emitting system, a laser distance measuring system and a workpiece bearing system; a laser beam emitted by a femtosecond laser device of the laser emitting system is reflected to a beam splitter through a plane mirror, and then, the focus of the laser beam is located in the H position above the surface of a workpiece through a focusing lens; the laser beam emitted by the femtosecond laser device is reflectedto the beam splitter through the plane mirror, and then, the focus of the laser beam is located in the H position through the focusing lens; and after receiving a signal fed back by a laser distance measuring instrument, the computer calculates and displays the distance between the light emergence spot of the focusing lens and the H position, and the computer controls the H position to be in the position 1-1.5 mm above the surface of the workpiece. According to the underwater laser shock non-die incremental forming device and method, femtosecond laser breaks down water and induces shock wavesto serve as a force source, through the nonlinear absorption characteristic of a transparent medium to laser ultrafast in focusing, the water serves a restraint layer and also serves an absorption layer, that is, the restraint layer and the absorption layer are integrated, and workpiece incremental forming is achieved.

An optical information recording/reproducing device is provided with a first light source 20a for emitting recording light 22a, a second light source 20b for emitting reproducing light 22b, an objective lens 6 for focusing the emitted lights from the both light sources 20a, 20b on an information recording medium including a recording region 3 capable of three-dimensional recording and photodetectors 19a, 19b for detecting reflected lights 7a′, 7b′ from the information recording medium, and records information on recording layers 1a to 1e utilizing a nonlinear absorption phenomenon. At the objective lens 6, an average rim intensity of the recording light 7a is lower than that of the reproducing light 7b.

The invention discloses a nonlinear optical absorption cross section measuring method. According to the invention, degenerate and non-degenerate nonlinear absorption section spectra can be measured atthe same time. The measurement process is automatic, efficient and rapid. According to the invention, the working wave band is from 380nm to near-infrared 1064nm, and the nonlinear performance measurement of the super-continuum wide spectrum can be realized. A zoom optical system with a large entrance pupil diameter is used as a weak signal acquisition lens, so that weak signals can be effectively extracted from background noise; the root-mean-square diameter of an image point on the axis of the zoom optical system is 100-150 micrometers, and the divergence angle 2alpha of the image point onthe axis is 30.6 degrees, so that optical fiber coupling conditions are well matched, and the coupling efficiency of spatial light coupled into optical fibers is improved; and the system measurement sensitivity is greatly improved.

The invention discloses a method for manufacturing ultra-diffraction limited nanometer graphics. The method includes: growing a double-layer phase transition material on a substrate; selecting properstepping on a double-layer phase transition material film for laser direct writing; moving the above steps 1) and 2) on a sample to perform laser direct writing once more; removing the upper phase transition material; performing positive adhesive development or negative adhesive development to obtain the ultra-diffraction limited nanometer graphics. According to the method, a mutation in a phase transition region between the upper layer and the lower layer is caused by the aid of threshold differences of the upper phase transition material and the lower phase transition material, the volume oflower phase transition is reduced, the ultra-diffraction limited nanometer graphics are favorably manufactured by the aid of the mutation, nonlinear absorption property of the material on high-energylaser enables laser energy acting on the lower phase transition material to be more concentrated in distribution, and the graphics are therefore reduced in size.

A refractive index writing system includes a pulsed laser source, an objective lens for focusing an output of the pulsed laser source to a focal spot in an optical material, and a scanner for relatively moving the focal spot with respect to the optical material along a scan region. A beam multiplexer divides the output of the laser source into at least two working beams that are focused to variously shaped focal spots within the optical material. A controller controls at least one of a temporal and a spatial offset between the focal spots of the working beams together with the relative speed and direction of the scanner for maintaining an energy profile within the optical material along the scan region above a nonlinear absorption threshold of the optical material and below a breakdown threshold of the optical materials.

A device and method for measuring linear absorption and nonlinear absorption of a material are provided; according to the method, a sample is irradiated with a short-pulse high-repeating-frequency laser through the high-sensitivity photothermic technique insensitive to scattered light, a phase-locked amplifier is used to measure linear absorption of the sample under multi-pulse accumulative action, a Boxcar integrator is used to measure nonlinear absorption of the sample under single pulse, and linear absorption and nonlinear absorption are measured at the same time, and the novel method and means are provided for studying absorption features of the material. The device and method have the advantages of insensitivity to scattered light and high efficiency.

The present invention is phthalocyanine compounds with peripheral siloxane substitution, as well as methods for making these compounds and various uses thereof, having the basic structure:

wherein

• • —W—X—Y-Z are peripheral groups comprising individual W, X, Y, and Z subgroups;
  • W is a linkage represented by the formula: -D-(R¹)_0,1—, where D=S or O;
  • X is: —(CH₂)_n—, n=2 to 8;
  • Y is a siloxane chain;
  • Z is an aryl or alkyl terminal cap;
  • M is two protons or a metal ion;

and forms a transparent film of high optical quality with large nonlinear absorption and thermal refraction, free of scattering from solid or liquid crystalline domains making them highly suitable for use as the active component in thin films, protective eye wear, and optical data storage applications.

The invention discloses a saturable absorption device based on a silicon quantum dot thin film and application thereof in a fiber pulse laser device. Silicon quantum dots with high three-order nonlinear coefficients are prepared into a thin film or are doped into a base material to form a composite thin film, and the thin film is put between single-mode or multi-mode fibers with specific mode field parameters; by using a self-focusing property of the thin film, the device can generate different transmission rates for input light with different intensity, and the absorption device is applied into the fiber pulse laser device, so that a method of Q-switch and mode-locked pulse method is realized. The saturable absorption device disclosed by the invention has extremely low insertion loss and adjustable nonlinear absorption parameters, the operating wavelength can overlay an invisible light-near-infrared band, and the parameter optimization range of the laser device can be improved, so that laser pulse output with an optimal performance is realized; and the saturable absorption device can be applied to the fields of photo-communication, photo-detection, biomedical imaging, distance measurement, sensing and the like.

The invention belongs to the field of intense laser protective materials of the military project and discloses a Sn porphyrin-polyaniline nonlinear absorption optical function material prepared by connection of covalent bonds. The nano-material has comparatively good nonlinear absorption performance. The invention mainly aims to develop the novel porphyrin covalent functionalized Sn porphyrin-polyaniline nonlinear absorption optical function material with good solubility for the problem existing in the current laser protective material and the limit of poorer solubility of a polyaniline material. In the Sn porphyrin-polyaniline nonlinear absorption optical function material, metal Sn porphyrin is covalently modified on the surface of polyaniline by the covalent bonds; the prepared organic-polymer photosensitive function material integrates the characteristics of porphyrin and polyaniline; a hybrid material has more excellent nonlinear optical property than a single material due to the synergistic effect of components, therefore, the Sn porphyrin-polyaniline nonlinear absorption optical function material has a good application prospect.