349 results about "Optical probing" patented technology

A passively mode-locked solid-state laser for emitting a continuous-wave train of electromagnetic-radiation pulses, the fundamental repetition rate of the emitted pulses exceeding 1 GHz, without Q-switching has an optical resonator, a solid-state laser gain element placed inside the optical resonator, an exciter for exciting said laser gain element to emit electromagnetic radiation having the effective wavelength, and a saturable absorber for passive mode locking. The laser gain element preferably consists of a laser material with a stimulated emission cross section exceeding 0.8x10-18 cm-2 at the effective wavelength. Typically, the laser gain element is made of Nd:vanadate. The saturable absorber is preferably a semiconductor saturable absorber mirror device. The laser is simple, robust, compact, efficient, and low-cost. It generates a relatively large average power of 100 mW and higher, which is useful for a number of optical probing and detection applications, in a beam which is substantially a fundamental spatial mode.

A device, system and method is disclosed in which small volume blood samples are subjected to shear forces and shear stresses between two parallel planar surfaces to which linear motion trajectories are imparted. The formation of clots or coagulation of the sample is measured from dynamic mechanical coupling which occurs between the two parallel planar surfaces. Detection of the coagulation response can be achieved through optical probing or by measurement of physical effects of the blood sample binding to the planar surfaces, and restricting movement thereof.

A passively mode-locked solid-state laser is designed to emit a continuous-wave train (51, 52) of electromagnetic-radiation pulses, the fundamental repetition rate of the emitted pulses exceeding 1 GHz, without Q-switching instabilities. The laser includes an optical resonator (3.1), a solid-state laser gain element (2) placed inside the optical resonator (3.1), a device (1) for exciting said laser gain element (2) to emit electromagnetic radiation having the effective wavelength, and a device (4) for passive mode locking including a saturable absorber. The laser gain element (2) is a laser material with a stimulated emission cross section exceeding 0.8×10−18 cm2 at the effective wavelength, and is made of Nd:vanadate. The saturable absorber (4) is preferably a semiconductor saturable absorber mirror (SESAM) device. Even higher repetition rates are achieved by operating the laser in the soliton regime. For use in fiber-optical telecommunication, the laser wavelength is preferably shifted to 1.5 μm by use of an optical parametric oscillator. The laser is simple, robust, compact, efficient, and low-cost. It generates a relatively large average power of 100 mW and higher, which is useful for a number of optical probing and detection applications, in a beam (51, 52) that is substantially a fundamental spatial mode.

The invention relates to a probe of a conducting atomic force microscope. The probe comprises: a substrate of a cantilever probe; a needle tip; and a conductive film, which is arranged at a surface of the needle tip. Besides, the material of the conductive film is graphene. Moreover, the invention provides a method that employs the probe to measure local conductivity of a semiconductor and a needle tip-free near-field optical detection method that employs the probe to measure a terahertz wave band. According to the invention, graphene is utilized, wherein the grapheme has the following characteristics that: the graphene is composed of carbon atoms and is thin to a monatomic layer; and the graphene is a semimetal two-dimensional thin material that has a zero gap; besides, the probe has advantages of good conductivity and high electron mobility; moreover, a Fermi surface can carry out self-adjustment with charging and discharging motions and a carrier injection potential is low. In addition, an electronic plasmon oscillating frequency of the graphene is just at a terahertz wave band; and the graphene has soft materials and strong stability on thermodynamics. The above-mentioned statements are physical bases on which the graphene is utilized to replace a traditional metal material as a plated film of a surface of an atomic force microscope probe, so that the above-mentioned limitations are broken through.

This invention relates to apparatus and methods for sensing terahertz radiation, in particular over an area, and to terahertz radiation imaging systems. A terahertz radiation sensor, the sensor comprising an optical beam input to receive an optical probe beam, a detector to modulate said probe beam responsive to terahertz radiation, and a photosensitive detector to provide an output responsive to said probe beam modulation. The sensor being configured to provide a first optical path between said optical beam input and said electro-optic detector and to provide a second optical path between said electro-optic detector and said photosensitive detector, and wherein said sensor further comprises a polarizer, said polarizer being located in both said first and said second optical paths. We further describe imaging systems for use with such a probe.

A system for probing a DUT is provided, the system comprising a tunable or CW laser source, a modulator for modulating the output of the laser source, a beam optics designed to point a probing beam at a designated location on the DUT, optical detector for detecting the reflected beam, and collection and signal processing electronics. The system deciphers perturbations in the reflected beam by detecting beat frequency between operation frequency of the DUT and frequency of the modulation. In an alternative embodiment, the laser is CW and the modulation is applied to the optical detector.

An optical detection system for detecting launch of an offensive projectile. The detection system includes an image detector array, an optical arrangement for focusing on to the image detector array, and a processing system associated with the image detector array. The processing system is configured to derive a series of frames from the image detector, to process the series of frames to identify a flash event and to generate and output that indicates a direction of the flash event.

A landmine detection and neutralization apparatus and method is disclosed. The apparatus to determine the location of landmines, comprises at least two detection modules utilizing different infrared, sound, and / or optical detection and a remotely operated miniature airborne vehicle, that may carry the detection modules at an optimum altitude over a surface that may contain landmines. The neutralization device may be a microwave, acoustic and / or infrared wave generator. The method for determining the location of land comprises using at least two different landmine detection techniques where the techniques are infrared, sound, and optical detection, operating the detection techniques in a close proximity to a surface that may contain landmines and maintaining this close proximity by operating a remotely operated miniature airborne vehicle. Neutralization may be achieved by directing microwaves or infrared waves at detected landmines.

An interventional device, e.g. a Vacuum Assisted Biopsy (VAB) needle, incorporating optical fibers such that biological tissue in a volume at a side of the interventional device can be substantially completely optically probed by optical spectroscopy. In a VAB embodiment, a plurality of optical fiber pairs connected to respective optical ports, are placed at opposite positions along the suction cavity, and they are readout subsequently allowing to make a map of the tissue properties along the place where the tissue will be cut by the VAB needle. Based on decision software in an optical console, it can be determined whether the tissue present in the cutting cavity is completely normal tissue or not, prior to actually performing the biopsy on the tissue. In this way a well defined end point for VAB is created. In one embodiment, the optical fibers are arranged in a wall structure of a thin sleeve which fits onto existing VAB needles, thus allowing the VAB needle to be upgraded with an optical probing capability.

Techniques for detecting optical spectral properties of a target are described. The technique includes providing an optical carrier which has an optical frequency bandwidth which is narrow compared to the width of the narrowest spectral feature of the target to be determined. This optical carrier is then electro-optically modulated with an RF frequency chirp, creating an optical chirp probe beam with a frequency chirped optical spectrum having upper and lower frequency chirped sidebands that have amplitudes sufficient to be detected at a detector. The sidebands are frequency bands arranged symmetrically around the optical carrier frequency. The attributes of a sideband include a start frequency, bandwidth and chirp rate. A probe beam is generated with the sidebands and directed onto a target having a physical property with optical frequency dependence. An optical response signal resulting from an interaction between the probe beam and the target is detected. The optical frequency dependence of the physical property of the target is determined based on the optical response signal and the attributes of the sidebands.

The invention relates to the technical field of optical detection and provides a spectrum detection system for material component analysis and a detection method thereof. The spectrum detection system comprises a laser device, a spectrum signal collecting component, a light separating component and a material component analysis device with a door control function, wherein the laser device sequentially generates laser with at least two wavelengths and a synchronous signal; the spectrum signal collecting component collects an LIBS (laser-induced breakdown spectroscopy) signal and an RRS (retransmission request signal) spectrum signal which are generated after a sample to be analyzed is excited by two laser pulses respectively; the light separating component effectively separating the LIBS signal and the RRS spectrum signal with different wavelengths respectively; the material component analysis device with the door control function detects and receives the LIBS signal or the RRS spectrum signal separated by the light separating component according to the synchronous signal of the laser device and compares the existing spectrum information data to analyze the atom components and the molecule components of the sample so as to identify the components of the material. According to the invention, excitation, collection and detection of the LIBS signal and the RRS spectrum signal can be realized on one set of system by using single pulse laser, so that the atomic spectrum and the molecular spectrum of the material are obtained, and the components of the to-be-detected target containing various components or unknown components can be quantitatively analyzed.

This invention relates to apparatus and methods for sensing terahertz radiation, in particular over an area, and to terahertz radiation imaging systems.A terahertz radiation sensor, the sensor comprising an optical beam input to receive an optical probe beam, a detector to modulate said probe beam responsive to terahertz radiation, and a photosensitive detector to provide an output responsive to said probe beam modulation. The sensor being configured to provide a first optical path between said optical beam input and said electro-optic detector and to provide a second optical path between said electro-optic detector and said photosensitive detector, and wherein said sensor further comprises a polarizer, said polarizer being located in both said first and said second optical paths. We further describe imaging systems for use with such a probe.

The invention provides an airport runway foreign matter monitoring and removing guidance system and method, and belongs to the field of civil airline monitoring. The airport runway foreign matter monitoring and removing guidance system includes at least one detection device, a network exchanger, a master control center server and a master control center displayer; the detection devices are distributed at one side of an airport runway according to a preset interval; each detection device includes a radar detection unit, an optical detection unit and a control box; each radar detection unit is connected with the corresponding optical detection unit and the corresponding control box, and each control box is connected with the network exchanger; the network exchanger is connected with the master control center server; the master control center displayer is connected with the master control center server. Each radar detection unit and each optical detection unit are distributed on the corresponding unified detection device, the monitoring mode is unified, the distributed location is safe, and installation and maintenance are convenient.

The invention discloses an unmanned aerial vehicle invasion detection and identification system based on a visual sense and a method thereof. The system comprises a plurality of cameras, a target detection module and a target identification module. The target identification module comprises a movement track determination device, an optical flow characteristic determination device, a zooming controller and a characteristic matcher. The cameras are deployed around a monitoring area. After the target detection module detects moving targets, through track determination and optical flow characteristic determination, preliminary screening is performed on the targets and parts of non-unmanned-aerial vehicle targets are eliminated. The cameras are controlled to zoom so as to acquire a sharp image. Through a scale-invariant characteristic transform matching algorithm, matching identification is performed on the targets. In the invention, an optical detection device is adopted, a visual sense detection and identification algorithm is used, unmanned aerial vehicle invasion in a monitoring range can be rapidly and accurately detected and identified, the system and the method are suitable for places which have an anti-unmanned-aerial-vehicle demand, such as an airport, a prison and the like, and detection and identification capabilities of unmanned aerial vehicle invasion are increased.

An attachment 10 that is proximal to an optical probe 9 includes probe information holding means 39 that holds probe information such as a scanning technique and an optical path length or the like. When the optical probe 9 is connected (attached) to an observing device 6, probe information detecting means included in the observing device 6 automatically detects the probe information held in the optical probe. Based on the detected probe information, a scanning technique and an optical path length of reference light are set to values suitable to an actually connected optical probe 9.

A method for analysis of blood components or parameters is disclosed where a probe having an excitation outlet and a response inlet is placed in proximity to or in contact with a tissue of an underside of a patient's tongue over a big vein in the tongue so that an excitation signal exits the outlet, produces a response which enters the inlet for detection and analysis.

A Brillouin optical distributed sensing device and method includes a structure for generating an optical pulsed signal and an optical probe signal. Includes is a circulation component for directing the optical pulsed signal to a sensing optical fiber and for directing an optical measurement signal with Brillouin scattering information arising from the sensing optical fiber toward a detection apparatus. Also included is an optical routing component for configuring the device to allow generating: (i) according to a first configuration, an optical measurement signal with stimulated Brillouin scattering information resulting from the interaction of the optical pulsed signal, and an optical probe signal propagating in the sensing optical fiber in a direction opposite to the optical pulsed signal, or (ii) according to a second configuration, an optical measurement signal with spontaneous Brillouin scattering information resulting from the propagation of the optical pulsed signal in the sensing optical fiber.

A system for probing a DUT is provided, the system comprising a tunable or CW laser source, a modulator for modulating the output of the laser source, a beam optics designed to point a probing beam at a designated location on the DUT, optical detector for detecting the reflected beam, and collection and signal processing electronics. The system deciphers perturbations in the reflected beam by detecting beat frequency between operation frequency of the DUT and frequency of the modulation. In an alternative embodiment, the laser is CW and the modulation is applied to the optical detector.

A microscope for producing an image of a target using THz radiation. The microscope comprises a source for providing an optical pump pulse and an optical probe pulse; a THz emitter for activation by pump pulse to emit a THz pulse that irradiates the target to form a target-modified THz pulse; a THz detector for modulating the probe pulse with the target-modified THz pulse to create a modulated optical probe pulse characteristic of the target; an optical detection system for modifying and detecting the modulated optical probe pulse and converting the modulated optical probe pulse to electronic information; and a processor for receiving the electronic information and producing an image of the sample using the electronic information. The THz emitter and detector comprise one or more EO crystals. The target is positioned on one of the EO crystals in a near-field of the THz pulse.

A simple and effective all-optical system, producing a multilevel coded optical signal based on the M-ASK technology and by the minimized equipment. The novel all-optical modulation technique for optical M-ASK generation is based on nonlinear interaction between optical signals, say between N 2-ASK modulated pump signals having extinction ratio ER1 and a single 2-ASK modulated optical probe signal having extinction ratio ER2. According to the invention, a 4-ASK optical signal can be obtained using just a single binary modulated pump optical signal and a single binary modulated probe optical signal.

The invention discloses a measuring device and a measuring method for micro-channel velocity distribution, including a microscope, a double-pulse laser, a photons detector, a synchronous controller and a processor. The method includes the following steps: 1) regulating all instruments to a working state; 2) injecting fluorescent particle solution into micro channel and drive the liquid flowing in the channel; 3) adjusting the vertical position of lens to the clearest imaging position on the bottom surface of the micro channel; 4) the distance between two light spots on the same particle irradiating by the double-pulse laser should be within 20 to 50 pixels; 5) continuously shooting multi-frame images under the irradiation of the double-pulse laser; 6) adjusting the focal plane of lens to a new position and shoot multi-frame images again; 7) repeating the step 6) and shooting images in different positions. The invention has the advantages of high optical sensitivity, high spatial resolution of flow speed detection and high adjustable accuracy of vertical displacement.

An all-fiber Doppler lidar wind field detection system comprises a laser emission system, an optical receiving system, a frequency discrimination and optical detection system and a signal processing system, wherein the frequency discrimination and optical detection system is connected with the signal processing system; the laser emission system and the optical receiving system are connected with the frequency discrimination and optical detection system through multi-mode / single-mode converters; the laser emission system emits laser light into the atmosphere; the optical receiving system receives backscattering light of atmospheric molecules and couples the backscattering light into multimode fibers, then, the backscattering light is fed into the signal processing system after entering the frequency discrimination and optical detection system for processing through the multi-mode / single-mode converters, and wind speed information is obtained after the backscattering light is processed. A fiber M-Z interferometer is used as a frequency detector, the wavelength range is wide, the selectivity of a laser light source is high, the ability to resist external interference is high, and spectral resolution and light splitting efficiency are high; in this way, the stability of detection is improved, detection accuracy is high, and the all-fiber Doppler lidar wind field detection system is convenient to use.

A method of analyzing a remotely-located object includes the steps of inducing a volume of an ionized ambient gas to emit pulsed terahertz radiation directed toward a targeted object by focusing an optical pump beam in the volume and ionizing another volume of the ambient gas to produce a sensor plasma by focusing an optical probe beam in the other volume of ambient gas. The interaction, in the sensor plasma, of the focused optical probe beam and an incident terahertz wave, which is produced by the targeted object reflecting, scattering, or transmitting the pulsed terahertz radiation, produces a resultant radiation. Detecting an optical component of the resultant radiation emitted by the sensor plasma facilitates detection of a signature of the targeted object imposed onto the incident terahertz radiation.

A scanned optical system for use in optical probing applications provides a large Field of View (FOV) for objective lenses having high Numerical Aperture (NA), such as Solid Immersion Lenses (SIL's). This enables high resolution imaging of semiconductor devices for such applications as laser probing, TIVA / LIVA, OBIRCH, and photon emission timing analysis. A hybrid scanning optics configuration is disclosed to provide high resolution imaging over a small area along with low resolution imaging over a large area.

The invention discloses a non-contact photoacoustic detecting method based on optical interferometry. The method comprises the following steps of S1, photoacoustic stimulation, S2, optical coherent detection, S3, balance adjustment and S4 detecting window locking. The invention further discloses a non-contact photoacoustic detecting device based on optical interferometry and used for achieving the method. According to the method, the problem that acoustic coupling media must be used in current photoacoustic imaging is solved, and the application range of photoacoustic imaging is widened. High sensitivity is achieved, light spots of probe light can be focused to the micrometer or submicron scale, and high lateral resolution is achieved. Optical detection is adopted, high-speed scanning is easy, and therefore imaging speed can be increased. Real-time detection is carried out to interfere with system sensitivity, balance adjustment is carried out on probe light intensity, and photoacoustic detection is carried out in the state of the highest system sensitivity. The non-contact photoacoustic detecting device based on optical interferometry is further provided, and the stability and repeatability of imaging can be effectively improved.

A method of analyzing a remotely-located object includes the step of illuminating at least a portion of a targeted object with electromagnetic radiation to induce a phase transformation in the targeted object, wherein the phase transformation produces an emitter plasma, which emits terahertz radiation. The method also includes the step of ionizing a volume of an ambient gas to produce a sensor plasma by focusing an optical probe beam in the volume and the step of detecting an optical component of resultant radiation produced from an interaction of the focused optical probe beam and the terahertz radiation in the sensor plasma. Detecting an optical component of the resultant radiation emitted by the sensor plasma facilitates detection of a characteristic fingerprint of the targeted object imposed onto the terahertz radiation produced as a result of the induced phase transformation.

The invention discloses an optical detection and microimaging method of micro-nano particles not subjected to the influence of the background. The diameter range of the micro-nano particles is 10nm to 400nm. The method is characterized in that an oil-immersed microobjective with high numerical aperture is used for exciting surface plasma resonance of a precious metal / medium interface, a light field in a focus plane is scattered through the micro-nano particles, is collected by another microobjective to be used as signal light which is subjected to polarized heterodyne interference together with reference light, the amplitude and the phase of longitudinal polarized state of transmitting light are extracted so as to detect and image the micro-nano particles. By controlling the exciting condition of the surface plasma, the particles with the diameter being greater than 400nm do not produce the surface plasma resonance under the excitation, so that the large-particle background is removed, and the micro-nano particles can be detected and imaged in the background with the existence of the large particles.

The invention provides a design method that can independently regulate the relative position of the two channels in a double-channel light filtering piece, adopting a bisymmetric structure based on Fabry-Perot etalon. It is different from traditional narrow-band light filtering piece in regulating independently the positions of the two channels by changing the thickness of several middle layers, respectively, and thus overcomes the position coherence phenomenon caused by the position regulation of channel. It introduces the design of the light filtering piece and concrete structure as well as the calculated spectrum characteristic of the double-channel band-pass light filtering piece, etc. It can be applied in the fields of optical detecting apparatus, space technique and so on.

An optical fiber temperature sensor based on a diamond NV color center comprises an optical fiber, a microwave transmission antenna and diamond containing the NV color center, and the optical fiber isused for transmitting exciting light and collecting fluorescence emitted by the NV color center; the microwave transmission antenna is a copper wire surrounding the optical fiber ceramic ferrule andis used for transmitting microwaves to control the ground state energy level of the NV color center so as to perform optical detection magnetic resonance; the diamond containing the NV color center islocated on the end face of the optical fiber, temperature changes can cause changes of the ground state energy level of the NV color center, and then the diamond is used for temperature sensing. Thesensor is simple in structure and high in practicability, high temperature detection sensitivity can be achieved, the sensor is not affected by magnetic field noise and microwave jitter in the environment during detection, and high robustness is reflected. Diamond is used as a main sensing part and has a very high heat conduction coefficient, so that the temperature sensor can respond to millisecond-order temperature change.