226 results about "Nonlinear optics" patented technology

The invention discloses a spirofluorene xanthene material and a preparation method and an application method thereof, and relates to application of the material in the fields such as organic electroluminescence, photovoltaic cell, organic electrical storage, organic nonlinear optics, chemical and biological sensing, organic laser and so on. The material has the following structure. The material has the advantages that (1) the material is prepared through a one pot process and has simple steps and mild conditions; (2) the material has the advantages of spirobifluorene materials, and shows high thermal stability and vitrification temperature; and (3) the material has high hole or electron mobility and so on. An electroluminescent device prepared by utilizing the material achieves satisfactory results in aspects such as illumination, luminous efficiency, voltage withstand stability and so on.

In conducting laser annealing using a CW laser or a quasi-CW laser, productivity is not high as compared with an excimer laser and thus, it is necessary to further enhance productivity. According to the present invention, a fundamental wave is used without putting laser light into a non linear optical element, and laser annealing is conducted by irradiating a semiconductor thin film with pulsed laser light having a high repetition rate. A laser oscillator having a high output power can be used for laser annealing, since a non linear optical element is not used and thus light is not converted to a harmonic. Therefore, the width of a region having large grain crystals that is formed by scanning once can be increased, and thus the productivity can be enhanced dramatically.

The invention relates to new polymerizable mesogenic or liquid crystalline compounds comprising a terminal cyclohexylphenyl group wherein the phenyl group has polar substituents, to polymerizable mesogenic or liquid crystalline mixtures and anisotropic polymers prepared thereof, and to the use of the new compounds and the mixtures and polymers prepared thereof in optical and electrooptical devices, adhesives, synthetic resins with anisotropic mechanical properties, cosmetics, diagnostics, liquid crystal pigments, decorative and security applications, nonlinear optics, optical information storage, electronic devices like organic field effect transistors (FET or OFET) or electroluminescent devices.

A system for detecting haemozoin in a sample, said system including a light source for exciting the sample with an optical signal to generate a non-linear optical response, and a detector for detecting the generated non-linear optical response from the excited sample. A method for detecting haemozoin in a sample, the method including exciting the sample with an optical signal to generate a non-linear optical response from the sample, and detecting the emitted non-linear optical signal from the excited sample.

The invention relates to a normal-temperature normal-pressure femto-second CARS (Coherent Anti-stokes Raman Spectroscopy) time-resolved spectrum measuring system which relates to the technical field of nonlinear optics and solves the problem of multiple limiting factors of traditional femto-second CARS time-resolved spectrum measuring experiment. Beams output by a femto-second laser are adjusted through a series of reflectors and optical delay lines by the system to form three bundles of beams which have approximate energy and are respectively positioned on three peaks of a square on the vertical direction of the beams, the beams are focused to a sample pool and then emit a new beam along a specific angle, i.e. a CARS signal, the CARS signal is filtered through a filter plate, then received by a probe and input to a monochromator, the data acquisition of an electrical signal converted by a photomultiplier is carried out by utilizing BOCCAR, and the data are input to a computer for data processing. The invention can carry out femto-second CARS time-resolved spectrum measurement under the experimental conditions of normal temperature and normal pressure and is applicable for the femto-second CARS spectrum measurement of gas samples and liquid samples in a static sample pool.

The invention relates to a passive mode-locking ultrashort pulse all-fiber laser with a waveband of 2.0 microns and belongs to the field of a laser technology and nonlinear optics. The passive mode-locking ultrashort pulse all-fiber laser with the waveband of 2.0 microns mainly comprises a laser pumping source, a pumping combiner, thulium-doped or thulium-holmium-codoped rear earth doped fibers, a circulator, a saturable absorber, a laser beam splitter, an isolator, a fiber bragg grating, a polarization controller and the like. The thulium-doped or thulium-holmium-codoped rear earth doped fibers are used as a gain medium; the saturable absorber is used as a passive mode-locking device; and the output of an ultrashort laser pulse which is in the waveband of 2.0 microns and has high pulse energy is realized. Due to the adoption of the all-fiber structure design, the passive mode-locking ultrashort pulse all-fiber laser with the waveband of 2.0 microns has the advantages of simple structure, high environment stability and the like, and the industrialization application is easy to realize.

The invention discloses a double-coating large-mode-area photon crystal flysecond laser directly obtaining micro joule-level single pulse energy, belonging to the field of laser technique and nonlinear optics, where the laser main body is based on double-coating large-mode-area photon crystal optical fiber of polarization-protection structure and adopts high-power LD laser to directly pump; the laser uses grating pair to compensate dispersion, starts mode locking with the help of semiconductor saturable absorber mirror (SESAM), and controls polarization by wave plate and polarization beam splitter and implements tunable output; laser resonant cavity keeps net positive dispersion inside and runs in self-similar mode locking mode and outside-cavity dispersion compensation is made on the output pulse and the pulse is 100-200fs wide. And the advantages: the laser has good stability, and the output pulse has high energy and high repeating frequency. And the invention can effectively avoid split of pulse running at high energy.

The invention relates to new polymerisable mesogenic or liquid crystalline compounds comprising a laterally substituted cinnamate group, to polymerisable mesogenic or liquid crystalline mixtures and anisotropic polymers prepared thereof, and to the use of the new compounds and the mixtures and polymers prepared thereof in optical and electrooptical devices, adhesives, synthetic resins with anisotropic mechanical properties, cosmetics, diagnostics, liquid crystal pigments, decorative and security applications, nonlinear optics, optical information storage, electronic devices like organic field effect transistors (FET or OFET), electroluminescent devices, or as chiral dopants.

An optoelectronic transducer comprises a unipolar, intraband active region and a micro-cavity resonator. The resonator includes a 2D array of essentially equally spaced regions that exhibits resonant modes. Each of the spaced regions has a depth that extends through the active region and has an average refractive index that is different from that of the active region. The refractive index contrast, the spacing of the spaced regions, and the dimensions of the spaced regions are mutually adapted so that the array acts as a micro-cavity resonator and so that at least one frequency of the resonant modes of the array falls within the spectrum of an optoelectronic parameter of the active region (i.e., the gain spectrum where the transducer is a laser; the absorption spectrum where the transducer is a photodetector). In a first embodiment, the transducer is an ISB laser, whereas in a second embodiment it is a unipolar, intraband photodetector. In other embodiments, the laser is a surface-emitting ISB laser and the photodetector is a vertically-illuminated detector. In another embodiment, a nonlinear optical material is optically coupled to the micro-cavity resonator, which in one case allows an ISB laser to exhibit bistable operation.

The invention discloses an all-fiber pulsed laser, and belongs to the field of laser technology and nonlinear optics. The all-fiber pulsed laser includes a pump source (1), an optical combiner (2), a first gain fiber (3), a second gain fiber (4), a first reflective fiber Bragg grating (5), a second reflective fiber Bragg grating (6), an optical isolator (7), a full reflection mirror (8) and a circulator (9), and adopts a structure of linear cavity or annular cavity. By use of the rare earth-doped gain fibers as a laser modulator, with no additional external modulation source and an all-fiber structure, ultrashort pulse laser output of high stability, high power, high energy and high efficiency is achieved. Compared with a semiconductor saturable absorption mirror (SESAM) and graphene (Graphene) modulation Q, mode-locking technology, the all-fiber pulsed laser employs gain fiber for direct pulse modulation, has the advantages of simple design, compact structure and high stability, and is easier to industrialize.

A laser pulse shape measuring system to measure the pulse shape of pulses generated by a pulsed laser. Each pulse includes a pulse width and a peak wavelength. The system includes: a beam splitter coupled to the laser to separate each of the pulses into a test pulse and a probe pulse; a pulse width compression means coupled to the beam splitter to compress the pulse width of each probe pulse; a controllable delay means to control a time offset between each test pulse and a corresponding probe pulse; a nonlinear optical medium arranged such that the test beam path and the probe beam path intersect within it to generate wavelength converted pulses corresponding to intersecting pairs of pulses; a detector coupled to the nonlinear optical medium to detect the pulse energies of the wavelength converted pulses; and a processor to determine the pulse shape of the laser pulses.

An amplified commonly mode-locked and/or Q-switched external cavity laser device with a plurality of gain elements and a plurality of amplifying elements is described. The device produces amplified optical pulses of picosecond to nanoseconds duration. The amplified pulses can be used in applications requiring large optical pulse energy and also high average optical power, such as material processing, nonlinear optics, extreme UV spectroscopy, and generation of x-rays.

A nonlinear optical crystal having a chemical formula of Y_iLa_jAl_kB₁₆O₄₈, where 2.8≦i≦3.2, 0.8≦j≦1.2, i and j sum to about four, and k is about 12 is provided. The nonlinear optical crystal is useful for nonlinear optical applications including frequency conversion. Nonlinear optical crystals in a specific embodiment are characterized by UV blocking materials (e.g., some transition metals and lanthanides) at concentrations of less than 1,000 parts per million, providing high transmittance over portions of the UV spectrum (e.g., 175-360 nm).

A harmonic holography (H²) technique and system that combines holography and nonlinear optics that enables holographic recording of 3D images with femtosecond framing time are provided. The H² technique records holograms with second harmonic (SH) signals scattered off specialized nanocrystals that are functionalized to label specific protein or other biomolecules in a living organism. The capability of generating second harmonic radiations is specific to materials with noncentrosymmetric crystalline structures only, and χ⁽²⁾ vanishes for all other types of materials. Therefore, a sharp contrast is formed when particles of noncentrosymmetric structures are dispersed in a medium of other species, pumped at a fundamental frequency, and imaged at the second harmonic frequency. The new scheme described herein provides a sound basis for a new type of contrast microscopy with enormous potential in molecular biomedical imaging.

The present disclosure relates to a generally-applicable measurement technique based on coherent quantum enhancement effects and provides embodiments with nonlinear optics. The technique utilizes parametric nonlinear processes where the information-carrying electromagnetic quanta in a number of electromagnetic modes are converted phase coherently to signature quanta in a single mode or a few modes. The phase coherence means that while the quanta before conversion may have unequal or uncertain phase values across the modes, the signature quanta converted from those different modes have the (near) uniform phase. This can lead to significant increase in the signal to noise ratio in detecting weak signal buried in strong background noise. Applications can be found in remote sensing, ranging, biological imaging, field imaging, target detection and identification, covert communications, and other fields that can benefit from improved signal to noise ratios by using the phase coherent effect.

A device and a system, based upon Deep Optical Scanning (DEOS), for the detection of certain cancers such as breast cancer and the determination of their response to therapy. DEOS is based upon the nonlinear optical interaction of incident laser generated light with tissue. The cancers may either be subsurface or on the surface. The system includes hardware and software components that form subsystems including: an Optical Electronic Subsystem, a Digitization Subsystem, a Parameter Computation Subsystem, an Archive, an Artificial Intelligence Subsystem, and a Presentation Subsystem. The device can be made portable and is non-invasive in its application to a patient. The system can be integrated into a hybrid architecture with other imaging techniques used for the detection of cancers.

The invention relates to an optical parameter oscillator, especially relates to a compact broadband spectrum independently-tunable dual-wavelength parameter oscillator and belongs to the field of laser technology and nonlinear optics. The parameter oscillator comprises a pump laser, a polarization beam splitter, a reflector, a first controller, a second controller, a first coupling optical system, a second coupling optical system, a first chamber mirror, a second chamber mirror, a third chamber mirror, a fourth chamber mirror, a first crystal, a second crystal, a first spectroscope and a second spectroscope. According to the invention, an optical parameter oscillation resonant cavity is adopted to realize dual-wavelength outputting; independent tuning of the center wavelength and wavelength intervals of output light can be independently tuned in a broadband spectrum scope. The power of two paths of output light with different wavelengths can be independently tuned. The pump light source is a non-polarization light source. The compact broadband-spectrum independently-tunable dual-wavelength parameter oscillator of the invention has characteristics of being simple in structure, low in cost, reliable in working and convenient in operation.

The invention relates to a method for improving photoluminescence efficiency of an upconversion material. The method is used for preparing the NaY1-x-yYbxEryF4 upconversion material containing nano-silver particles by a co-sintering process, and the photoluminescence efficiency of the NaY1-x-yYbxEryF4 upconversion material containing the nano-silver particles can be effectively improved by effectively mixing the nano-silver particles with the upconversion material and utilizing a resonance enhancement property of a high-energy local electric field of localization surface plasmon polaritons to the nonlinear optical process. The method disclosed by the invention has the benefits that the emission peak intensity at 411nm, 524nm, 544nm and 657nm can be improved by above 15% under the excitation of incident photons in the wavelength of 980nm, the gain which is above 20% can be obtained in a full spectrum range between 300-800nm, and a fluorescence enhancement effect is significant.

The invention relates to a 2-micrometer waveband all-polarization-maintaining locked-mode ultrafast pulse fiber laser, and belongs to the field of the laser technology and nonlinear optics. The 2-micrometer waveband all-polarization-maintaining locked-mode ultrafast pulse fiber laser mainly comprises a laser pump source, a polarization-maintaining pump combiner, a polarization-maintaining thulium-doped or thulium and holmium co-doped optical fiber, a polarization-maintaining circulator, a polarization-maintaining isolator, a saturable absorption body or saturable absorption mirror, a polarization-maintaining coupler and a polarization-maintaining passive optical fiber. The thulium-doped or holmium-doped or thulium and holmium co-doped optical fiber is used as a gain medium, and the saturable absorption body or the saturable absorption mirror is combined with a 8-shaped resonant cavity to be collectively used as a passive locked-mode device, so that the 2-micrometer waveband, low-power pump, all-polarization-maintaining and mixed locked-mode ultrafast pulse is outputted. By adopting the structure, the all-optical-fiber welding is realized. The 2-micrometer waveband all-polarization-maintaining locked-mode ultrafast pulse fiber laser has the advantages of low pump power, stable locked mode, simple structure and stable and reliable system locked mode, and not only can be used as a laser light source with excellent performance, but also can be used as a signal seed source to be further amplified.

The invention belongs to the technical field of light beam conversion, in particular to a method for generating a bezier-like light beam through an optical fiber end face growth microcone. The methodcomprises the following steps of: depositing a photopolymer liquid reagent on the end face of a single-mode optical fiber, coupling green laser into the single-mode optical fiber through a lens, and reacting with the photopolymer liquid reagent deposited on the end face of the single-mode optical fiber to form a polymer microcone; wherein the light beam is converted into a bezier-like light beam after passing through the polymer microcone formed by the end face of the optical fiber. The shape of the microcone is controlled by light polymerization parameters such as green laser power, laser exposure time and oxygen diffusion concentration. The working bandwidth of the microcone covers the whole visible light region and even the near infrared band, and can have more than 30 concentric ringsat most, and the generated Bezier-like beam has self-recovery property. The method has the advantages of high efficiency, low cost and convenience, and can be widely applied to the fields of particlecontrol, optical imaging, nonlinear optics, photoetching, micro-manufacturing and the like.

The invention relates to a solid laser with adjustable pulse width from a hundred picoseconds to a nanosecond and solves problems of complicated structure and high cost of a narrow-pulse-width large-energy laser structure obtained by means of a mode-locking technique in combination with amplification technology. Linear polarized light generated by a seed light laser successively passes an isolator, a shaper 1, a polarization device 1, an amplifier 1, and a polarization device 2 and then enters a SBS pulse compressor. Light returned from the SBS pulse compressor successively passes the polarization device 2, the amplifier 1, the polarization device 1, the shaper 2 and the amplifier 2 and then exits from amplifier 2. The solid laser is simple in structure, lower in cost compared with a product in the prior art, large in output energy, good in the quality of output light beams, and suitable for the fields of laser medicine, nonlinear optics, precision machining and laser communication.

The invention discloses a super-resolution microscopy method and system based on saturated pumping-stimulated emission detection and belongs to fields of super-resolution microscopy imaging and nonlinear optics. The system comprises a light source module, a detection module and a processing module, wherein a sample is put between the light source module and the detection module, the light source module comprises a first light source emitting excitation light, a second light source emitting reading light, a modulation device, a dichroscope and a galvanometer scanner, the detection module comprises a photo detector, the photo detector is connected with a lock-in amplifier, and the lock-in amplifier is in communicated connection with the processing module. On the basis of confocal microscopy,saturated excitation light is introduced and is limited in time domain, so that the sample can be entangled with a fluorescent high-order harmonic signal; in addition, another beam of reading laser is introduced, so that to-be-emitted fluorescence is emitted in a form of stimulated emission light, finally, a high-order harmonic signal of the stimulated emission light is demodulated through phase-locked detection, so as to obtain a final imaging result.

The present invention relates to a method for raising output power of fibre-optic laser and quality of its optical spectrum and beam, belonging to the field of laser and optoelectronics. Said invention is characterized by that it utilizes forward phase conjugation and backward phase conjugation to suppress the stimulated Raman scattering effect and compensate the effects of harmful nonlinear optics and thermal aberration, etc. so as to raise the output power of fibre-optic laser and quality of its optical spectrum and beam.

The invention relates to a passive mode-locking laser based on graphite alkene having an epitaxial growth on a SiC substrate and is directed to the fields of laser technology and nonlinear optics. The passive mode-locking laser mainly comprises a SiC substrate, graphite alkene having an epitaxial growth on the SiC substrate, a doped fiber, a gain medium, a pumped source, a wavelength division multiplexing device, a laser beam splitter, a single-mode fiber, an annular device, a polarization controller and the like. A mode-locking laser output having high stability and high impulse energy is realized through utilizing the characteristic of saturable absorption of graphite alkene. Graphite alkene having an epitaxial growth on the SiC substrate is characterized by high repeatability, good thermal conductivity and strong operationality. Therefore, graphite alkene having an epitaxial growth on the SiC substrate is easier to be applied into the passive mode-locking laser at a low cost and a large scale.