42 results about "Resonance fluorescence" patented technology

A grating-based sensor is disclosed that has a grating structure constructed and designed for both evanescent resonance (ER) fluorescence detection and label-free detection applications. One and two-dimensional gratings are also disclosed, including gratings characterized by unit cells with central posts, central holes, and two-level, two-dimensional gratings. A readout system for such sensors is also disclosed. Various applications for the biosensors are described, including cell-based assays for assessing the effect of drug compounds on cell function. A biosensor embodiment optimized for a luminescent response at two different wavelengths is also described. Such luminescent response could be produced by fluorescence (either native or from an attached fluorophore), phosphorescence, chemi-luminescence, or other luminescence technology. Two different luminescence technologies could be combined on the same biosensor chip.

The invention discloses a gadolinium (III)-carbon quantum dot and a preparation method thereof, and application thereof in a magnetic resonance-fluorescence double-modal imaging probe, and belongs to the technical field of preparation of a medical image material. The method comprises the following steps: 1) carrying out thermal treatment on a precursor, and generating a pyrolysis product; 2) adding the pyrolysis product to an alkaline solution to carry out ultrasonic dispersing treatment, so as to obtain turbid liquid; 3) filtering the turbid liquid by a waterborne microporous filter membrane to obtain filtrate containing the gadolinium (III)-carbon quantum dot; (4) dialyzing and drying the filtrate containing the gadolinium (III)-carbon quantum dot to obtain the gadolinium (III)-carbon quantum dot. The method is simple and feasible, low in demands on equipment, easy to control reaction conditions, and free of participation of an organic reagent; the rolled gadolinium (III)-carbon quantum dot can be evenly and stably dispersed into water, has excellent magnetic resonance response and photoluminescence properties, and is applicable to the magnetic resonance-fluorescence double-modal imaging probe.

The invention relates to a whole day photon counting laser radar device and a method, which comprises an emission system consisting of a laser, an expander and a reflector, a receiving system consisting of a telescope, an optics filter and a photoelectric detector, and a central control device connected with the photoelectric detector with a software. The invention is characterized in that the wavelength of the laser and the optics filter are chosen to match with the fraunhofer absorption line wavelength of the solar spectrum; the intense absorption is adopted to reduce the intensity of a solar back light by 80 to 90 percent and to lead the laser radar to have good photon counting ability under the back light condition in days. The invention is characterized in that the day detection signal-noise ratio and the detection distance are greatly improved, which effectively improves the whole day high-performance working ability. Besides, the invention is widely suitable for the laser radarof detecting weak signal such as Mie dispersion, Rayleigh dispersion, Raman dispersion and atom resonance fluorescence, etc.

A method for classifying a sample based upon a complete spectral analysis. The sample is illuminated with penetrating radiation and an initial complete spectral analysis is performed based on spectral resolution of resonant fluorescence lines emitted at the surface, or within the volume, of the sample. If the initial complete spectral analysis yields the composition of the sample to within acceptable limits, analysis values are output to the user. Otherwise, further analysis, informed by the results if the initial complete spectral analysis, is performed.

The invention discloses an adaptive narrow-linewidth semiconductor laser frequency stabilization device comprising a semiconductor laser, a beam collimating system, volume gratings, a heating device, an atomic gas chamber, a fluorescence measurement device and a signal processing and control system. The semiconductor laser, the beam collimating system and the volume gratings form an external chamber. The external chamber emergent laser spectrum is narrowed in comparison with that of the freely operating semiconductor laser 1 under the volume grating narrowband backward diffraction feedback effect. A part of emergent laser is incident to the atomic gas chamber to excite alkali metal atoms to generate resonance fluorescence. The fluorescence measurement system detects a fluorescence signal and inputs the fluorescence signal to the signal processing and control system. The signal processing and control system changes the grating temperature by regulating the heating power of the heating device in the volume gratings so as to change the emergent laser central wavelength. The adaptive narrow-linewidth semiconductor laser frequency stabilization device has the advantages of effectively enhancing pumping system spectrum stability, use convenience and environment adaptability.

The invention discloses a nondestructive container detection method based on the Compton gamma light-nuclear resonance fluorescence. The method comprises the following steps: (1) putting a Compton gamma light source on one side of a container to supply gamma light beams, and putting energy spectrometers on the two sides of the container, wherein included angles of 90 degrees and -90 degrees are formed between the energy spectrometers in the horizontal plane and the direction of an incident gamma beam respectively for performing energy spectrum measurement; (2) identifying nuclear resonance fluorescence characteristic peaks of various nuclides according to the distribution of measured energy spectra so as to further obtain possible nuclide type information in the container; (3) putting a flow intensity detector on the other side, opposite to the side in which the light source is arranged, of the container, and measuring the number of rays passing through different container positions by horizontally and vertically scanning the container to obtain position information and ray intensity information; and (4) putting nuclide evidential foils with different thicknesses between the container and the flow intensity detector, repeatedly executing the step (3), and comparing the ray intensity value with the ray intensity value measured in the step (3). According to the method, the various nuclides can be identified quickly and accurately, the signal to noise ratio is improved, the photographic reproduction dosage is reduced, and the scanning time is shortened.

The invention discloses a nanometer probe for testing DNA through combination of fluorescence intensity and fluorescence polarization, and belongs to the technical field of nucleic acid detection. The nanometer probe comprises fluorescent protein, a capturing probe, a reporting probe, and nanometer gold particles. The fluorescent protein is taken as a donor and connected with the capturing probe; the nanometer gold particles are taken as a receptor and connected with the reporting probe; the capturing probe and the reporting probe form an energy transfer donor and receptor pair through complementary pairing of parts of basic groups; and the capturing probe and target DNA are in complete complementary pairing. The nanometer probe is combined with fluorescence intensity parameters and fluorescence polarization parameters with high sensitivity, thereby achieving non-amplification DNA high-sensitivity detection; and through utilization of opposite variation tendencies of fluorescence intensity and fluorescence polarization in a process of forming and vanishing resonance fluorescence energy transfer, a specific value of fluorescence intensity to fluorescence polarization is introduced, and a detection signal of DNA is amplified.

The present invention dislcoses a kind of double wavelength laser radar capable of detecting high altidude atmosphere in wide 30-110 Km range. In the hardware configuration basically the same as that in a common sodium layer fluorescent laser radar, the laser radar combines the two operating mechanism of Rayleigh scattering and sodium layer resonance fluorescence. By means of double wavelength emission and spitted spectroscopic double fiber reception, one laser radar can be used to detect the atmosphere in both middle altitude and high altitude of wide 20-110 Km range simultaneously and complete all the functions of both Rayleigh scattering laser radar and sodium layer resonance fluorescence laser radar.

The invention discloses a spectral measurement method based on a wide-spectrum light source and spectral scanning laser radar. The measurement method comprises the following steps: adjusting the transmission wavelength of the adjustable filter in a time-sharing manner; under a specific transmission wavelength, filtering laser pulses from the wide-spectrum pulse laser through an adjustable filter,emitting the wide-spectrum pulse laser to a detection target after being subjected to pulse excitation amplification, filtering echo signals through the same adjustable filter to obtain signals to bedetected, and measuring echo intensity of the signals to be detected; and measuring echo intensities under different transmission wavelengths to obtain a detection target spectrum. The related spectrum scanning laser radar adopts a time division multiplexing technology and an optical switch gating technology to support the implementation of the method. According to the invention, the solar and skybackground noise can be filtered to the greatest extent, the Brillouin signal, the Raman signal and the resonance fluorescence signal are isolated, the detection spectrum purity and the signal-to-noise ratio are improved, and the system integration and stability are improved by adopting an all-fiber structure. Spectral signals of an underwater profile can be extracted, and the method is an important supplement based on passive water color remote sensing at present.

The invention provides a novel laser sodium guide star system. The novel laser sodium guide star system comprises a laser transmitting module, a signal receiving module, a system control module and a near space vehicle platform. The near space vehicle platform is arranged in the airspace which is 20km above the ground and below the sodium layer in the upper atmosphere. The laser transmitting module is arranged on the near space vehicle platform. Lasers transmitted by the laser transmitting module irradiate sodium atoms in the sodium layer in the upper atmosphere to generate resonance fluorescence, a sodium guide star is obtained, and the lasers are then received by the signal receiving module. The laser sodium guide star system is constructed on the basis of the near space vehicle platform, the luminance of the laser sodium guide star is greatly improved on the basis of existing laser source power, the influences of atmosphere turbulences on light beam transmission are effectively avoided, the obtained laser sodium guide star is higher in position stability and small in error, the correction effect and work performance of a self-adaption system can be improved, and the novel laser sodium guide star system has great market popularization value.

The invention relates to a nuclear resonance fluorescence-based pulse gamma ray energy spectrum measuring system and method. The device comprises lead collimators, a HPGe detector and a specific target sheet; the lead collimators and the specific target sheet are sequentially disposed in the beam direction of pulse gamma rays to be measured; the HPGe detector is located to one side of the pulse gamma rays to be measured; and an included angle between the HPGe detector and the beam direction ranges from 90 degrees to 120 degrees; a plurality of target materials are stacked so as to form the specific target sheet; and the energy level of each target material is within the energy range of the pulse gamma rays to be measured. The method includes the following steps that: 1) a HPGe detector isadopted to detect the number R of photons emitted by the pulse gamma rays to be measured during nuclear resonance fluorescence; 2) photon density is calculated; and 3) and Gaussian fitting is performed on the basis of the photon density, so that the energy spectrum distribution diagram of the pulse gamma rays to be measured is obtained. With the method of the invention adopted, a pulse gamma ray energy spectrum measurement experiment is simple to set, later-stage calculation is simple, and measurement accuracy is high.