854 results about "Self-focusing" patented technology

Systems and methods for laser scribing provide extended depth affectation into a substrate or workpiece by focusing a laser beam such that the beam passes into the workpiece using a waveguide, self-focusing effect to cause internal crystal damage along a channel extending into the workpiece. Different optical effects may be used to facilitate the waveguide, self-focusing effect, such as multi-photon absorption in the material of the workpiece, transparency of the material of the workpiece, and aberrations of the focused laser. The laser beam may have a wavelength, pulse duration, and pulse energy, for example, to provide transmission through the material and multi-photon absorption in the material. An aberrated, focused laser beam may also be used to provide a longitudinal spherical aberration range sufficient to extend the effective depth of field (DOF) into the workpiece.

A Sagnac-like optical fiber sending device of low coherent twisted type is prepared as connecting optical source and photoelectric detector at a side of a coupler and connecting another side of said coupler to a closed loop formed by series-connecting various single-mode optical sending arms with 2x2 couplers. The closed loop is featured as out-setting single-mode optical fiber of high reflection surface and single-mode out-set optical fiber, using self-focusing lens and scan-reflector to form demodulation end of optical fiber and returning partial light back to light detector through said single-mode optical fiber.

The invention belongs to the radar technology field, discloses a high resolution spotlight SAR self-focusing imaging method based on two-dimensional self-focusing and mainly solves a problem that excellent focusing of a uniform imaging area can not be realized through a self-focusing algorithm in the prior art. The method comprises steps that an original echo signal of a target is received, after distance pulse pressure of the echo signal is carried out, crude envelope error and phase error compensation for the signal is carried out; distance direction FFT and azimuth solution linearity frequency modulation operation and two-dimensional interpolation operation are carried out; after distance direction IFFT of a result after two-dimensional interpolation is carried out, distance migration of a distance skipping unit is evaluated, and envelope error correction is accomplished; V non-superposed distance sub blocks are formed through uniform division along the distance direction, and a phase error of each sub block is evaluated; corresponding weights of distance units are respectively calculated, distance errors of the distance sub blocks are evaluated respectively, space-variant error evaluation is accomplished, azimuth direction IFFT of the data after correction is carried out, and thereby SAR images having the excellent focusing effect are acquired.

Planar sub-wavelength structures provide superlensing, i.e., electromagnetic focusing beyond the diffraction limit. The planar structures use diffraction to force the input field to converge to a spot on the focal plane. The sub-wavelength patterned structures manipulate the output wave in such a manner as to form a sub-wavelength focus in the near field. In some examples, the sub-wavelength structures may be linear grating-like structures that can focus electromagnetic radiation to lines of arbitrarily small sub-wavelength dimension, or two dimensional grating-like structures and Bessel (azimuthally symmetric) structures that can focus to spots of arbitrarily small sub-wavelength dimensions. The particular pattern for the sub-wavelength structures may be derived from the desired focus. Some examples describe sub-wavelength structures that have been implemented to focus microwave radiation to sub-wavelength dimensions in the near field.

A laser micromachining method is disclosed wherein a workpiece is milled using an incident beam from a laser beam focused above the surface of the workpiece. The incident beam is guided by a plasma channel generated by the incident beam. The plasma channel, which has a relatively constant diameter over an extended distance, is generated by continual Kerr effect self-focusing balanced by ionization of air beam defocusing.

A laser micromachining method is disclosed wherein a workpiece is milled using an incident beam from a laser beam focused above the surface of the workpiece. The incident beam is guided by a plasma channel generated by the incident beam. The plasma channel, which has a relatively constant diameter over an extended distance, is generated by continual Kerr effect self-focusing balanced by ionization of air beam defocusing.

The invention provides a measuring instrument with an optical fiber Mach-Zehnder interferometer and optical fiber Michdson interferometer arrays, which comprises a broad-band light source 1, a photoelectric detector 2, a 3dB optical fiber 2 multiplied by 2 coupler 3, the optical fiber Mach-Zehnder interferometer, a transposed 3dB optical fiber 2 multiplied by 2 coupler 7, optical fiber Michdson interferometers arrays 8 and 8', and a single-mode connecting optical fiber 9, wherein, the optical fiber Mach-Zehnder interferometer consists of an attenuator 4, a self-focusing lens 5, an axicon lens 6 with total reflection angle, and the connecting optical fiber 9. The measuring instrument with the optical fiber Mach-Zehnder interferometer and the optical fiber Michdson interferometer arrays utilizes a technique that measures strain and temperature at the same time, realizes the temperature compensation technique and the array arrangement of optical fiber sensors, realizes absolute measurement under the situation that the multiple sensors are not interfered by each other, lowers the cost of single-point measurement and ensures real-time measurement; furthermore, the measuring instrument has simple techniques and easy implementation, and as standard optical fiber communication elements are adopted as the optical fiber materials and devices, the measuring instrument has low cost, easy acquisition of the optical fiber materials and devices and easy popularization.

An Optical Tapped Delay Line (OTDL), which resolves multiple wavelength signals having extremely narrow wavelength spacing, is combined with other known optical devices to provide a wide variety of optical signal processing applications, including: multiplexing and de-multiplexing a multi-channel signal; adding a signal to, or dropping a signal from, a multi-channel optical signal; specialized coding processing such as generating code division multiple access signals; wavelength locking (stabilizing) a signal; filtering a signal; and analyzing and monitoring a signal spectrum. The OTDL spatially separates individual channels to allow separate processing on each channel. Fixed and tunable embodiments are identified in appropriate cases. Bulk, hybrid, and integrated optical embodiment and methods of fabrication are described, as are curved self-focusing and evanescent embodiments of OTDL devices. The devices and processes disclosed have particular application to dense wavelength division multiplexing (DWDM) and permit a significant improvement in the quantity of information that can be carried on DWDM signals while enhancing signal quality.

The invention discloses a structural light microscopic imaging system based on line scanning time-space focusing. The system comprises the components of a femto second laser device; an acousto-optical modulator which is used for periodically modulating light source strength according to a sine function; a line scanning module which is used for scanning in a linear focusing light spot direction and a vertical linear light spot function; a dispersion element which is used for generating a spatial chirp; a collimating lens which is used for focusing different frequency components after grating dispersion to a parallel transmission direction; a microscope module; and a synchronous control module which is used for performing synchronous controlling on the acousto-optical modulator, the line scanning module and the microscope module, thereby obtaining a reconstructed image. According to the structural light microscopic imaging system, the reconstructed image can be obtained through strength-modulated line scanning structural light illumination in a line scanning time-space focused scanning mode and strength change of synchronously modulated excited light, thereby improving resolution and contrast in line scanning time-space focusing and reducing excitation outside a focal plane caused by medium scattering.

The invention discloses a non-contact micro-vibration measuring system based on a non-equilibrium Michelson fiber-optic interferometer, which belongs to the technical field of fiber-optic sensing. The non-contact micro-vibration measuring system is characterized in that lights pass through a narrow-band light source, a coupler and the non-equilibrium Michelson fiber-optic interferometer in sequence, wherein one path of the lights irradiates to the surface of an object vertically by an optical-fiber self-focusing lens, then returns and is coupled into optical fiber; the other path of the lights is returned by a reflecting device at the tail end of the optical fiber of a reference arm; the two paths of lights pass through the coupler, a photoelectric coupler (PD) and a data processing module; simultaneously, the data processing module generates carriers waves to control a phase modulator on an interference arm; and finally, a result is obtained by a phase demodulation technology of a phase generation carrier (PGC) based on calculation of arc tangent (ARCTAN). The non-contact micro-vibration measuring system has the beneficial effects that due to the adoption of the combination of the Michelson fiber-optic interferometer and the phase generation carriers based on calculation of the arc tangent, the flexibility is high, the response is good, no influence by factors of light intensity and visibility drifting is caused, and the online measurement on non-contact micro-vibration can be realized.

The invention provides a PS-OCT-based three dimension visual nonnasality decayed tooth checking device and a checking method thereof. The method comprises: a polarized light beam is illuminated on an object to be checked by a self-focusing lens, a reflected light carrying the information of the object to be checked returns along the coming way, the reflected light carrying the information of the object to be checked and the reflected light from the exit end face of the self-focusing lens enter into the two arms of an interferometer and return to a coupler through a Faraday polariscope and perform interference; an optical fiber stretcher is adjusted to realize scanning in the longitudinal direction Z and synchronously the object to be checked is scanned in the horizontal direction X by a displacement platform to obtain the two-dimensional information of a certain cross section; the displacement platform is adjusted for carrying out scanning along the direction Y vertical to the cross section to obtain the plural two-dimensional images of different parts of the representative sample; the data is analyzed and processed with a software to obtain the structure and birefringence information of the object to be checked and reconstruct the three dimensional image thereof, and the result is displayed. The invention can realize high precise checking on the teeth without radiation, thus facilitating diagnosis on the decayed tooth.

The invention relates to a high-precision wide-range low-coherent interference shift demodulation device, which comprises a light source, an optical circulator, a self-focusing collimation lens, a fixed reflecting mirror, an optical fiber splicer, a beam extender lens, a polarizer, a birefringent optical wedge, a stair-shaped birefringent phase shifter, an analyzer, a planar array camera and a processing unit. A demodulation method comprises the following steps: dividing the light emitted from the light source into two parts after the light passes through the optical circulator and reaches the self-focusing collimation lens at the sensing side, wherein one part is directly reflected and the other part is reflected after entering the reflecting mirror fixed on an object to be detected, and the two parts of reflection light have an optical path difference (OPD); guiding the two parts of reflection light to pass through the optical circulator again so as to reach the optical fiber splicer and then reach the birefringent optical wedge and the stair-shaped birefringent phase shifter through the beam extender lens and polarizer; realizing the wide-range optical path difference (OPD) scanning under the combined action of the birefringent optical wedge and the stair-shaped birefringent phase shifter; generating an interference fringe behind the analyzer; receiving the interference fringe by using the planar array camera; and detecting the shift information through digital processing by a computer or an embedded system.

The invention provides a motion compensation method for bistatic synthetic aperture radar imaging based on a phase tracking algorithm. In the method, firstly, by designing a set of narrow-band filters, inhibiting the echo effects of the neighboring targets and acquiring the phase position information of the echo signal of strong scattering points, phase position compensation and direction compression are carried out on the neighboring distance unit, thereby acquiring a bistatic SAR imaging result with high accuracy; secondly, extracting bistatic SAR imaging processing parameters by directly using echo data can lower the cost of a bistatic SAR system; in addition, self-focusing technology which utilizes the echo data to process the signals can compensate the effect of the rapid disturbance which is difficult to be detected by a navigation system. The method provides technical supports for the study of advanced high-resolution radar imaging technology.

The invention relates to a self-focusing preprocessing method based on a short-time fractional order Fourier domain filter, which belongs to the field of synthetic aperture radar (SAR) signal processing. The method comprises the following steps of: (1) extracting a phase error signal of a single special showing point; (2) judging whether the phases of the phase error signal mainly are quadratic phase or not; (3) filtering noise in a transform domain: if the phases mainly are quadratic phases, using short-time fractional order Fourier domain filter; otherwise, using short-time Fourier domain filter; and (4) inversely transforming result time frequency to a time domain, estimating and compensating the phase error and realizing self-focusing preprocessing. The method effectively solves the problems of estimation and compensation of the phase error in a low-signal-to-noise ratio environment, especially the estimation and compensation of the quadratic phase error, and can obtain the main part of a phase error course and greatly improve the imaging quality after removing the phase error course from an original signal, thereby improving the signal-to-noise ratio of a special showing point signal.

An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

The invention provides a distributed fiber white-light interference sensor array based on tunable Fabry-Perot resonant cavity, which is composed of a duplex photoelectric device, a tunable Fabry-Perot resonant cavity, a single-mode connection fiber and a sensor, wherein the tunable Fabry-Perot resonant cavity is composed of a scanning prism, a self-focusing lens, and a single-mode optical fiber with partial reflection surface; the duplex photoelectric device is composed of a wide-spectrum light source with a common base, an emitter and a collector, a photodetector, and a beam splitter prism; the beam with a certain spectral width is emitted by the light source to the resonant cavity directly through the beam splitter prism and is reflected multiple times by the left and the right surfaces of the resonant cavity to obtain a signal light; and the signal light outputted from the right cavity surface enters the sensor through the single-mode connection fiber, reflected by the left and the right end faces of the sensor, returns along the original path to the resonant, and is outputted from the left cavity surface to the photodetector. The distributed fiber white-light interference sensor array has a common light path structure and has the advantages of good temperature stability, simplest optical fiber path structure, low cost and high practicality.

The invention provides a simplified multiplexing white light interference fiber sensing demodulating device, which comprises a single-fiber two-way optical transmitting / receiving module, an optical fiber resonant cavity, a single-mode transmission fiber, and an optical fiber sensing array, wherein the single-fiber two-way optical transmitting / receiving module is composed of a semiconductor light source as the transmitting terminal, a semiconductor photodetector as the receiving terminal and related devices packaged together; and an optical fiber annular cavity is composed of an optical fiber coupler, an optical fiber self-focusing lens and a movable corner reflector. The device can achieve enquiry and measurement of a plurality of optical fiber sensors by embedding the single-fiber two-way optical transmitting / receiving module and the optical fiber resonant cavity in the single-mode optical fiber, and has the advantages of simple structure, easy implementation, no length restriction of the transmission cable, no influence caused by the external environment, and good stability and reliability. The device can be used for the measurement of physical quantities such as distributed deformation, strain and temperature, and can be used for multi-task sensing, multi-element sensing, local strain sensing, large-scale deformation sensing, etc.

The invention discloses an improved high-resolution SAR (synthetic aperture radar) imaging self-focusing method. The method mainly comprises the following steps that: range pulse compression, preliminary movement compensation and range direction FFT are sequentially performed on radar echo signals, so that movement compensated radar echo signals and the simplified form of the movement compensated radar echo signals can be obtained sequentially; the simplified form of the movement compensated radar echo signals is multiplied by an azimuth Dechirp function; two-dimension interpolation is performed along the range and azimuth directions respectively; after two-dimension interpolated radar echo signals are obtained, IFFT is performed along the range direction, so that phase history-domain data can be obtained; envelope error compensation of the phase history-domain data can be accomplished through adopting an image shift SAR self-focusing algorithm, the phase error of the phase history-domain data of which the envelope error compensation has been completed can be solved through utilizing a conjugate gradient algorithm; after the phase history-domain data of which the envelope error compensation and phase error compensation have been completed are obtained, IFFT is performed along the azimuth direction, so that a high-resolution SAR image with an excellent focusing effect can be obtained.

The invention provides an FFBP SAR imaging-based autofocus method through which accurately focused SAR images can be obtained in eight steps. The method is based on an FFBP frame, phase gradient information of movement error is extracted by using phase difference information of adjacent sub-apertures of point targets, and movement error is estimated through an integration method and compensated to realize autofocus processing of high-accurate SAR images. Compared with conventional methods, the method is not affected by error order. Movement error of any orders can be estimated, and the robustness of autofocus algorithm is substantially improved. Error information is extracted by using phase difference of adjacent sub-apertures, which avoids repeated calculation of a nested overlapping sub-aperture method. Large-scale optimized searching is not required, computational burden is greatly reduced, and imaging time is shortened.

The invention discloses a micro optical probe of endoscope, which comprises an MEMS microscope, a circuit board, a self focusing optical assembly, a locating bottom plate and a housing; the micro optical probe of endoscope is characterized in that: the endoscope probe is designed by using integrated symmetrical structure, the MEMS microscope; the circuit board and the self focusing optical assembly are assembled on the locating bottom plate according to design requirements of optomechatronics to form a probe body, and a probe housing is formed by injection molding or casting and is tightly connected with the probe body. The housing opposite to the microscope surface of the MEMS microscope can be formed with an optical window, or the housing material is transparent to the used light. The probe housing is formed at a time by injection molding / casting technology, and this structure can protect the MEMS microscope from being influenced with environment factor and can bear a certain vibration impact and random shock; the sealed probe can work in various liquid environments; and large-batch and low-cost processing production of probes can be realized, and the aim of disposable probes will be fulfilled.

A laser processing method and apparatus capable of forming an extremely minute modified area not exceeding half the diffraction limit value of the laser wavelength used for processing without causing plasma in a processing object such as a dielectric material substrate or semiconductor material substrate. In this technology, attention is paid to the fact that new damage is caused even at laser intensity that does not cause plasma at all, and a laser beam (1) that has lower laser intensity than the laser intensity threshold at which plasma occurs (for example, approximately 1 / 1.5 of that laser intensity threshold) is convergently radiated into a processing object (10) using an irradiation optical system (20) accuracy-designed so as not to cause a self-focusing effect at the convergence location (3).

This invention relates to high voltage circuit current measurement optical inductor and its test method, wherein, the sensor head is of bar magnetic materials along line distribution input fiber; the basic path is composed of self focus lens, bias device, optical sensor head, test bias device, parallel output self focus lens and fiber and vertical output focus lens and fiber. The test current passes through ring conductor to establish parallel magnetic field with at least one basic light path. The multiple light paths each sensor head is of same distance separately connected to low voltage two photoelectricity converters to output voltage signal and vertical voltage to compute test current.

The invention belongs to the field of radar signal processing, and particularly relates to a sparse aperture ISAR self-focusing and lateral scaling method based on Bayesian learning. The method comprises the following steps: firstly performing sparse prior modeling on an ISAR image by using a Laplace layered model, and performing sparse reconstruction on the ISAR image by using a variational Bayesian method, wherein during the reconstruction of the ISAR image, a modified Newton iterative method is used to simultaneously estimate a phase error and a target rotational speed to achieve self-focusing and lateral scaling of the ISAR under the sparse aperture condition. The invention obtains the beneficial effects that: due to the sparse aperture ISAR self-focusing and lateral scaling method based on Bayesian learning, the self-focusing and lateral scaling of the ISAR under the sparse aperture condition can be realized, and the ISAR image with good focusing effect, high resolution and exactlateral scaling can still be obtained under the condition of sparse radar echo data aperture caused by the factors such as low SNR, strong interference and insufficient effective aperture, which has important engineering application value and can provide theoretical support for the design of a compressed sensing radar.

The invention discloses a self-focusing method for strip synthetic aperture radar images, and belongs to a self-focusing method for SAR images. The invention combines a phase gradient self-focusing PGA algorithm with a sub-aperture related MD algorithm to be applied to an algorithm PGA-MD in the self-focusing of strip synthetic aperture radar images. The method comprises the following steps: performing self-focusing processing on each sub-image by adopting the PGA algorithm to obtain high-precision sub-aperture phase error functions; calculating linear phase difference between sub-aperture phase error functions by utilizing the relationship between adjacent sub-images position phase offset and linear phase and applying the MD algorithm for realizing phase splicing; and finishing self-focusing processing for the strip SAR images. The invention substitutes the MD algorithm for traditional process of carrying out sub-aperture phase error function splicing based on the second derivative and improves the self-focusing effect of the strip SAR images.

The invention relates to a method and a device for generating a radial or angled polarization self-focusing Airy beam. The method includes regulating polarization states of a collimating Gaussian beam to obtain a linear polarization Gaussian beam polarizing along a certain direction; performing light splitting to obtain a transmission beam, emitting the obtained transmission beam vertically to a spatial light modulator loaded with a phase information graph and then emitting the beam out in a reflecting manner after phase modulation; performing light splitting to obtain a reflected beam, subjecting the reflected beam to Fourier transformation and then converging the reflected beam by a convex lens so as to obtain a linear polarization self-focusing Airy beam through an annular stop at the focus point of the convex lens; and finally carrying out radial or angled polarization conversion to obtain the radial or angled polarization self-focusing Airy beam. By the method, self focusing can be carried out without any optical focusing elements, the light intensity in front of the focus point is low, the light intensity at the focus point is increased, energy is concentrated, and accurate positioning is achieved. The method can be applied to the fields of particle arrestance, biological medicines and the like, and belongs to the technical field of applied optics. In addition, the device is simple in structure and high in stability and is adjustable.

Disclosed is a self-adapting self-focusing method in digital camera. The method comprises steps of: a. collecting original colorful image with digital camera; b. taking the central area in the original colorful image as sub image and cutting out with self-adapting window according to the resolution of the original image; c. converting the colorful sub image into gray-scale image; d. performing two dimensional DCT transformation on the gray-scale sub image and obtaining two dimensional DCT coefficients; e. performing self-adapting weight on the two dimensional DCT coefficients according to its frequency and calculating image clearness evaluation function; f. employing a global searching strategy to control the movement of the stepper motor according to the image clearness evaluation function and searching out clear focused-image.

Present invention refers to integrated ultraviolet-visible absorbing / fluorescence two-purpose flow-through cell, referring to liquid chromatograph detector. It includes cell body, light guide quartz capillary, polyetheretherketone liner tube, self-focusing lens, seal washer, gasket, optical fiber and liquid flow path pipeline. Said Light guide quartz capillary is set in polyetheretherketone liner tube and filled in pipe cavity of cell body, self-focusing lens set in light entry direction fixed and sealed with cell body by seal washer, gasket located between self-focusing lens and polyetheretherketone liner tube, gasket notch aligned flow path direction to fill excess space, entry optical fiber, outlet optical fiber and in and out liquid pipe respectively fixed in cell body by joint and sleeve chuck to form sealed flow path.

The invention discloses an image self-focusing method and realization system, which comprises the following steps: providing user end computer with machine measurement and focusing control function for the detected object; supplying charge coupler and industrial optical lens to gather the continual image due to measuring the Z axle of machine; providing the image acquisition card to gain the continual image; supplying the control card to send order for controlling the Z axle motor to move within the named scale; sending the focusing order to the initiating system; obtaining the image of charge coupler; predisposing the obtained image; calculating the present image articulation; judging whether the Z axle reaches in the focusing scale or second focusing; calculating the focal point according to the articulation; driving Z axle motor to reach and output the position of focal point.

The invention discloses a white-light interference lens center thickness measuring system and a method, and belongs to the technical field of optical precise measurement, so as to solve the technical problems that the prior lens center thickness measuring device is low in measuring precision and small in dynamic measuring range. The white-light interference lens center thickness measuring system comprises a supercontinuum source, a photodetector, a 1:1 optical fiber coupler, a measuring arm, a reference arm, a first optical fiber, a second optical fiber and a data processing unit, wherein the measuring arm comprises a third optical fiber and a focusing lens; and the reference arm comprises a fourth optical fiber, a self-focusing lens, a scanning angle reflector, a plane mirror, a displacement mechanism and a length-measuring interferometer system. The precision of the system can reach 0.2 mum(3sigma) and the dynamic range can reach 1.5m.

The invention relates to PID control based self-focusing lens ion exchange temperature control method and system. The method is characterized by adjusting a PD control parameter by using mode recognition in artificial intelligence and inference judgment in an expert system; the expert system sums up artificially adjusted experience and skills into a series of adjusting rule firstly, and then carries out analysis and judgment on controlled system information which is collected in real time, automatically selects an adjusting rule, compares a response curve of a controlled object with a control target curve and carries out repeated adjustment and comparison till a control target is met. The system mainly comprises a thermocouple (1), an adjustment amplifying circuit (2), data collecting cards (3 and 7), a computer (4), a photoelectric isolating circuit (5), and a thyristor power adjusting and temperature controlling circuit (6), wherein the thermocouple (1) is installed in a heat treatment furnace, and the computer (4) is provided with PID control software. The invention has high temperature control precision, can reduce the requirement on the automation level of equipment and is beneficial to reducing the production cost.