33results about How to "Suppress backscatter" patented technology

The invention discloses a laser strobe active night vision method for remote night monitoring. In the method, a one-frame multi-pulse and multi-door working mode is adopted, in one frame time of exposure of an imaging device, a pulse laser emits a laser pulse sequence, a strobing gate works according to a preset strobing pulse sequence, and the imaging device receives a plurality of target echo signals from a target, therefore, the purpose of light accumulation and signal enhancement is achieved. The invention has good working environmental suitability, and can normally work under the condition of low visibility. Since a long-distance target can be observed at night by using the low-power pulse laser, the cost of the system is greatly reduced, the laser security of the system is improved,and especially the security of eyes is improved.

The purpose of the present invention is to provide a light-diffusing element that has a high haze value, is strongly diffusing, and has a smooth surface, reducing backscatter. This light-diffusing element has the following: a matrix that contains a resin component and an ultrafine-particle component; and light-diffusing fine particles dispersed within said matrix. Some of the resin component osmoses into the light-diffusing fine particles, and the distance to which the resin component osmoses into the light-diffusing fine particles is at least 90% of the mean diameter of the light-diffusing fine particles in this light-diffusing element. The arithmetic-mean surface roughness (Ra) is less than or equal to 0.04 mum.

The invention discloses a laser difference imaging detection method and a device for the same. The method comprises the following steps: performing range-gated imaging to obtain n frames of retroreflected images of n slices of a region to be detected in a one-frame one-pulse one-gate exposure manner; dividing the n frames of retroreflected images into m information frames and n-m background frames according to a grayscale threshold value; calculating differences of the m information frames and the background frames to obtain m enhanced information frames of the m information frames, and dividing the m enhanced information frames into k bubble information frames and m-k pseudo information frames by adopting a trained classifier; calculating a grayscale mean value and modulation time delays of the k bubble information frames respectively, and performing fitting to obtain a spatial distribution curve of bubbles along with the time delay; obtaining a range of a bubble region and yield of the bubbles according to the spatial distribution curve, wherein m, n and k are all natural numbers not smaller than 1. According to the method and the device, the range and the yield of the bubble region can be accurately detected, and the method and the device have the characteristics of high accuracy, high adaptability and high flexibility, and is significant for underwater bubble detection and analysis.

The invention discloses an underwater optical imaging device with axial multi-sensors, which includes an optical system, a first image sensor and a second image sensor, wherein the optical system receives the target light beam and the target beam formed by the suspended particles after the imaging target receives light. Backscattering, the first image sensor and the second image sensor are installed on the optical axis of the optical system, receive images of different focal plane positions, and propagate between the first image sensor and the second image sensor according to the target beam and backscattering The equivalent optical point spread function of the image is differentially processed to extract the target information. The invention utilizes the difference between the back scattering and the transfer function of the imaging target in the optical system to suppress the back scattering and obtain clear underwater long-distance target images.

The invention discloses a range gating super-resolution three-dimensional imaging device and method. The range gating super-resolution three-dimensional imaging device comprises a touch screen display (8), a central processor (9), a time schedule controller (10), a pulse laser (11), an illuminating optical lens (12), a gating area array imaging device (13) and an imaging optical lens (14), wherein the pulse laser (11) and the illuminating optical lens (12) are connected to form an illuminating unit; the gating area array imaging device (13) and the imaging optical lens (14) are connected to from an imaging unit; and the touch screen display (8), the central processor (9) and the time schedule controller (10) are connected to form a system control and display unit. According to the invention, the problems of poor instantaneity and sensitive noise disturbance of the traditional range gating three-dimensional imaging are solved; and the range gating super-resolution three-dimensional imaging device and method disclosed by the invention have the advantages of good adaptability and high flexibility and can be used for realizing the fast high-resolution three-dimensional imaging of a target.

The present invention provides a fluorescent light source device that suppresses the backscattering of the excitation light when the wavelength conversion member is irradiated with excitation light, and at the same time can emit the fluorescence generated inside the wavelength conversion member to the outside with high efficiency, thereby enabling Obtain high luminous efficiency. This fluorescent light source device is a fluorescent light source device provided with a wavelength conversion member composed of a phosphor excited by excitation light, wherein the wavelength conversion member forms a surface-side periodic structure on a surface serving as an excitation light receiving surface, A rear side periodic structure is formed on the rear surface, and a light reflection surface is provided on the outside of the rear surface.

A process for producing a light-diffusing element is provided by which a light-diffusing element having a high haze and high diffusing properties and reduced in backward scattering can be produced at low cost with high productivity. The process for producing a light-diffusing element comprises a step in which a matrix-forming material comprising a resin-ingredient precursor and an ultrafine-particle ingredient is brought into contact with fine light-diffusing particles, a step in which at least some of the precursor is infiltrated into an inner part of the fine light-diffusing particles, and a step in which the precursor that has infiltrated into the inner part of the fine light-diffusing particles and the precursor that has not infiltrated into the fine light-diffusing particles are simultaneously polymerized to form a matrix comprising the resin ingredient and the ultrafine-particle ingredient and simultaneously form a concentration gradation region in the vicinity of the inner side of the surface of the fine light-diffusing particles.

The invention discloses an optical stereo sampling in-situ detection method capable of acquiring zooplankton information. The method comprises the steps that laser pulse is transmitted by a pulsed laser and is reflected through zooplankton in a stereo sampling area, and a target echo signal is returned; when the target echo signal reaches a gating imaging device, a gating door of the gating imaging device is opened to receive the target echo signal, in-situ detection imaging is conducted on the zooplankton in the stereo sampling area, and an underwater two-dimensional strength image acquired by sampling is output; abundance information of the zooplankton is acquired according to the acquired behavior information, quantity information, size information of the zooplankton in the stereo sampling area through combining the underwater two-dimensional strength image and the volume of the stereo sampling area. By means of the method, the problems that in an existing in-situ detection imaging method, the real non-invasive and non-disruptive in-situ detection can not be achieved and the sampling area is uncertain are solved, the quantifiable optical stereo sampling area can be formed, and the acquisition of the non-disruptive stereo data of the zooplankton is achieved.

The invention discloses a double-loop parallel resonant gyroscope system and a double-closed-loop digital demodulation method thereof, including a tunable laser Laser, and the output light of the tunable laser is split into two paths of clockwise and counterclockwise light by a signal beam splitter. Enter the acousto-optic frequency shifter, electro-optic modulator, fiber coupler, hollow photonic bandgap fiber resonator, photodetector, digital lock-in amplifier in sequence, and form a frequency closed-loop feedback through the tunable laser and the acousto-optic frequency shifter respectively . The double-ring hollow-core photonic bandgap fiber structure allows clockwise and counterclockwise light waves to propagate independently in independent resonant cavities, which can improve temperature stability and effectively suppress non-reciprocal effects such as optical Kerr effect and Rayleigh backscattering noise. The double-closed-loop digital demodulation method locks the optical frequencies in the forward and counterclockwise optical paths at their respective transmission resonant frequencies, making the system work in the linear region, effectively improving the linear range of angular velocity detection and the linearity of the scale factor.

The invention discloses an image target seeking laser imaging distance measurement method and an image target seeking laser imaging distance measurement device. The method comprises the following steps of: imaging environment where a target is positioned in a non-gating imaging mode, and outputting a digital panorama to realize image target seeking; opening a distance measurement function, outputting a target-containing panoramic frame, selecting the target by a user, and opening the distance measurement function; obtaining a background frame in a distance measurement timing mode, constructing spatial slices with triangular distance energy envelope through distance gating imaging, performing slice scanning on a foresight field, and outputting slice frames; and when a target distance is subjected to inversion, performing differential processing on all the slice frames and the background frame to obtain new slice frames in which background influence is eliminated, and automatically calculating distance information of the target based on a mapping relation between the image gray scale ratio of a main window area among adjacent new slice frames and a distance energy ratio, which is established according to a distance gating echo broadening effect, by using a system, so that target distance measurement is finished. The method and the device are high in adaptability and easy to operate, target distance measurement is easy to realize, and particularly the problem that the distance of a small target is difficult to measure can be solved.

The invention discloses a time-correlated single photon counting wake detection device and an operation method thereof, belonging to the field of laser underwater wake target detection. It includes a laser emitting component, a laser receiving component and an information processing component. Both the laser emitting component and the laser receiving component are electrically connected to the information processing component. The component transmits the start electrical signal; the laser receiving component is used to receive the reflected light reflected by the bubbles in the wake, and transmits the termination electrical signal to the information processing component synchronously; the information processing component is used to receive the light from the laser emitting component The start electrical signal and the termination electrical signal from the laser receiving component complete the measurement of the photon flight time interval and the analysis of the time-correlated single photon counter, and finally calculate the target distance. The invention can realize the detection of underwater weak wake echo signals, and overcomes the technical limitation of low sensitivity existing in the traditional technology.