51 results about "Image intensifier" patented technology

This invention discloses an all-weather reconnaissance and alarm device, comprising a laser illumination component, an ICCD / ICMOS gating component, and an integrated processor. The laser illumination component uses high peak power pulsed laser light for illumination assistance, enhancing target brightness. The ICCD / ICMOS gating component is used to achieve high-gain photoelectric conversion of weak optical signals. Specifically, the ICCD / ICMOS gating component eliminates or reduces the influence of sunlight through "ultrafast adaptive imaging + light decay," enabling the component to operate in the linear region with the optimal signal-to-noise ratio for the target. Simultaneously, the ICCD / ICMOS gating component integrates a high-speed CCD / CMOS image sensor. Without changing the delay time, a higher image intensifier repetition frequency results in a smaller increase in delay time. Through ultra-high-speed image acquisition, it fully utilizes the energy of each laser pulse, enabling imaging of targets at different distances and high-speed moving targets. The integrated processing component focuses on controlling the ultrafast adaptive adjustment duration, the interval between auxiliary illumination and gating opening, and high-precision gain control.

We present a ground-based laser system for searching, ranging, and tracking that actively illuminates small resident space objects (RSOs) in low Earth orbit (LEO) and observes position and transit-time of reflections, enabling orbital custody of most one-to-few centimeter-sized objects. A diode-pumped alkali laser (DPAL) augmented with mode-locking and Q-switching serves as an illuminator and offers exceptionally high spectral brightness due to its output beam's sub-nanosecond pulse duration and picometer-level spectral linewidth. Kilohertz fast-rastering enables interrogations of distinct few-meter-sized sky-patches at megahertz rates. Paired on the observation side with one or more telescopes outfitted with Faraday anomalous dispersion optical filters (FADOFs), image intensifiers, multi-pixel arrays, and nanosecond timing, the combined system could offer nearly background-free discoveries of RSOs every hour, even during daytime. Periodically re-flashing previously discovered objects to maintain orbit custody expends only a small fraction of total observing time.

The invention provides a photon event camera, which comprises an acquisition module and a processing display module, and is characterized in that the acquisition module is used for acquiring photon events and comprises an image intensifier, a coupling light cone, a sensor and a gating unit; the image intensifier is used for amplifying an incident weak light signal, the coupling light cone is connected with the image intensifier and the sensor and is used for transmitting the amplified light signal, and the sensor receives and detects the amplified light signal and then outputs a detection signal; the sensor outputs a plurality of pixel event clusters generated by the plurality of photon signals as detection signals to the upper computer; the processing display module identifies a pixel event group formed by a single photon signal as a photon event, identifies a plurality of pixel event groups generated by a plurality of photon signals as a plurality of photon events, and displays and outputs the photon events corresponding to a space coordinate and a time coordinate. The method is suitable for measuring photon signals in a weak light scene, and has single-photon-level sensitivity; and the method is small in generated data volume, low in data volume and suitable for long-time acquisition.

The invention discloses a high-precision detection system and a high-precision test method for the uniformity of an output image of a low-light-level image intensifier. In the system and the method, an image output by an anode of an image intensifier is imaged on a focal plane by an optical lens, an imaging light spot is divided into two paths by a semi-transparent and semi-reflecting mirror: one path forms an imaging area observation light path through a magnifying lens and a camera or human eyes, and is used for selecting and confirming a test area and a scanning starting and ending point; the other path of light enters a high-precision detector after passing through an adjustable diaphragm, the output light current of the high-precision detector is converted into a voltage signal through a micro-current meter, and the voltage signal is acquired in real time by an acquisition card in the process that the one-dimensional operating mechanism scans along the horizontal diameter direction of the output image of the image intensifier at a constant speed, so that an output image uniformity curve is generated; and obtaining an image uniformity test value through the ratio of the maximum value to the minimum value of the curve. According to the invention, superposition errors caused by light source nonuniformity and pixel inconsistency are reduced, and high-precision and repeatable uniformity measurement consistent with human eye impression is realized by a test result.

The utility model discloses a multiple adjustment night vision lens for optical experiments, which belongs to the field of optics and comprises a low-light night vision device composed of an objective lens, an image intensifier and an eyepiece, the objective lens is connected with the eyepiece through a connecting tube, and the image intensifier is located inside the connecting tube. Compared with the prior art, the utility model has the advantages that the distance between the objective lens and the image intensifier is adjusted through the engagement connection of the displacement thread at the outer wall end of the objective lens and the translation screw at the output end of the brushless motor, and the brushless motor is controlled by the remote control system; in this way, the angle needing to be rotated can be rapidly determined according to the displacement data of the displacement thread of the objective lens, and rapid rotation is completed through the brushless motor, so that the adjustment data of the magnification of the objective lens is greatly increased.

The present application provides an image intensifier tube circuit board, an image intensifier tube module, and a night vision device. The image intensifier tube circuit board comprises a circuit substrate and an image intensifier tube electrical connection structure arranged on the circuit substrate. The image intensifier tube electrical connection structure comprises a positive spring contact and a negative spring contact which are fixedly arranged on the circuit substrate, and at least one of the following optionally arranged on the circuit substrate: an intermediate spring contact, a plug connector, and crown spring connectors. The arrangement of at least one of the intermediate spring contact, the plug connector, and the crown spring connectors enables electrical connection with image intensifier tubes of other models, thereby allowing compatibility with image intensifier tubes of multiple models, and allowing users to upgrade the performance of existing night vision devices by replacing existing image intensifier tubes with image intensifier tubes of different models.

There is disclosed a gated power supply for a night vision system includes an input terminal to receive source power, and output terminal to electrically couple to a photocathode, a first voltage source to source a positive or neutral voltage to the photocathode, a second voltage source to source a large negative voltage to the photocathode, and a switching circuit to switch between the first voltage source and the second voltage source on a duty cycle, wherein the switching circuit comprises an optical switch.

The invention discloses a high-speed flow velocity acquisition method based on stripe imaging, and belongs to the technical field of aerodynamics test. The purpose of improving the high-speed flow velocity measurement precision is achieved. A measurement system is established and comprises a femtosecond laser, a multi-pass compressor, a reflector I, a reflector II, a reflector III, a plano-concave lens, a plano-convex lens, a high-speed camera, an image intensifier, a telephoto lens, a fixed connection device, a computer device and a synchronous signal generator. Constructing a time sequence control and multi-delay gating acquisition method; calculating a scale conversion parameter; a sequential control and multi-delay gating acquisition method is utilized, an image is acquired based on a measurement system, image processing is carried out based on a corresponding relation between image pixel coordinates and actual physical sizes, and the high-speed flowing speed based on fringe imaging is calculated. The method is clear in process, high in system integration level and suitable for speed measurement under the transient high-speed flow condition, and has good engineering applicability and measurement reliability.

A method and system for determining concentricity of a multiple layer golf ball are disclosed herein. One or more images of a golf ball are generated using an X-ray source, a camera or a digital detector, and an image intensifier. An edge detection algorithm is preferably utilized. The method also includes calculating Y,Z center coordinates of the a best fit diameter or ellipse of the inner edge layer and outer edge layer of the multiple layer golf ball.

The invention discloses a high-voltage insulation processing method of an image intensifier. The method comprises the following steps: step 1, sleeving a high-voltage-resistant heat-shrinkable sleeve on the outer side of a high-voltage electrode wire; stripping the heat-shrinkable sleeve and an insulating layer of the high-voltage electrode wire to expose a wire core; 2, arranging a wire core, and performing button manufacturing along one direction; 3, the core heads on the two sides are connected; 4, a temperature control soldering iron is used for welding the hooking connection points, and scaling powder is smeared; step 5, completing an on-resistance test; step 6, coating epoxy glue on a welding spot, sleeving a first layer of sleeve, and performing hot blowing; sleeving a second layer of sleeve, repeating to the middle position of the first layer of sleeve, and performing hot blowing; step 7, assembling the welding spot joint in an insulating groove made of a polyimide material; and 8, wrapping ports of the first layer of sleeve and the second layer of sleeve by using silicon rubber at the same time, and fixing the wire harness at the bottom of the insulating plate. The invention has the characteristics of good insulating property, high dielectric strength, firm mechanical connection, high space environment adaptability and outstanding damage resistance.

The present application relates to image intensifier, to solve the problem that the MCP recovery time of the image intensifier cannot be measured accurately, and proposes a method for measuring the MCP recovery time of the image intensifier, comprising: arranging a CMOS camera at the output end of a fluorescent screen; generating two same period pulse signals of M1 and M2 through a signal generator to drive the same light source; closing M1 and opening M2 to obtain the original output light intensity of the fluorescent screen through the CMOS camera; synchronously outputting the pulse signals of M1 and M2, increasing the delay time between the pulse signals of M1 and M2 at certain time intervals in turn, and obtaining the corresponding output light intensity of the fluorescent screen under different delay times through the CMOS camera; closing M2 and opening M1 to obtain the corresponding pulse afterglow of the fluorescent screen under the corresponding delay time through the CMOS camera; calculating the corresponding MCP recovery degree according to the original output light intensity, the output light intensity and the pulse afterglow of the fluorescent screen, and when the value of the MCP recovery degree is equal to 1, the corresponding delay time is the MCP recovery time.

This utility model discloses a detection device for a low-light image intensifier, comprising a light source, an integrating sphere assembly, a dark box, and a detection component arranged sequentially. The dark box contains a clamp for mounting the low-light image intensifier, and an optical channel is provided between the light source, the integrating sphere assembly, and the dark box. The dark box includes a top plate with a mounting through-hole corresponding to the fluorescent screen of the low-light image intensifier. The detection component includes an eyepiece and a detection camera. The eyepiece is detachably connected to the mounting through-hole via a first adapter. The detection camera is located above the top plate, and a light-shielding tube is connected to its lower part. The lower end of the light-shielding tube is detachably connected to the mounting through-hole via a second adapter. This utility model integrates camera detection and visual detection into a single setup by connecting the eyepiece and the light-shielding tube of the detection camera to the same mounting through-hole via the first and second adapters, respectively, effectively improving the detection efficiency of the imaging uniformity of the low-light image intensifier.

The invention discloses a motorized high-speed wind tunnel femtosecond laser molecular marker speed measurement system, and belongs to the technical field of femtosecond laser molecular marker speed measurement. The problem of flow field measurement of integral movement is solved. The system comprises a movable femtosecond laser source platform, a plano-convex lens, a telephoto lens, an image intensifier, a high-speed camera and a computer device, femtosecond laser emitted by the movable femtosecond laser source platform penetrates through the plano-convex lens and irradiates a flow field area to be measured, the movable femtosecond laser source platform is connected with the image intensifier and the high-speed camera, the high-speed camera is connected with the image intensifier and the computer device, the image intensifier is connected with the telephoto lens, and the telephoto lens is connected with the computer device. The telephoto lens is used for shooting a to-be-measured flow field area irradiated by the femtosecond laser. According to the invention, the femtosecond laser, the temperature control module, the sequential control unit and the light path shaping component are packaged in the same movable platform in a centralized manner, so that the measurement system has good overall stability and deployment flexibility in a wind tunnel environment.

The application relates to a light-absorbing material glass for an optical fiber image transmission element and a preparation method and application thereof. The light-absorbing material glass for the optical fiber image transmission element comprises the following components in mole percentage: 68.0-78.0% of SiO2, 1.0-9.0% of Al2O3, 2.0-10.0% of B2O3, 1.0-10.0% of Na2O, 3.0-10.0% of K2O, 0.1-1.5% of MgO, 0.1-3.0% of CaO, 0.1-0.5% of SrO, 0.1-1.5% of NiO, 0.1-1.2% of Co2O3, 0.1-0.8% of MnO2 and 0.1-0.8% of Nd2O3. The light-absorbing material glass for the optical fiber image transmission element can solve the black-and-white display compatibility problem of the optical fiber image transmission element and a low-light-level image intensifier, and perfect black-and-white display compatibility with P45 fluorescent powder is realized.

The invention discloses a range gating imaging system based on pulse phase shift. Comprising a digital control unit used for generating M laser pulse signals and shutter control signals, M laser driving modules, M groups of laser diodes, and an optical fiber beam combiner used for combining laser output by each group of laser diodes, the imaging unit receives a shutter control signal and comprises an image intensifier and a driving module thereof, and the image intensifier and the driving module are used for performing gating imaging on a target under the control of the shutter control signal; wherein M is greater than or equal to 2, repetition frequencies of the laser pulse signals are the same, but phases have difference values; each laser driving module is connected with a laser pulse signal output end of the digital control unit; and each group of laser diodes is connected with one laser driving module, and each group of laser diodes outputs laser under the driving of corresponding laser pulse signals.

The utility model relates to the field of optical imaging and mechanical design, and discloses a single-lens light-incoming multi-Cmos imaging device, which comprises an optical focusing lens, an image intensifier is arranged at the bottom of the optical focusing lens, an installation assembly is arranged at the bottom of the image intensifier, the installation assembly is provided with a focusing lens and a CMOS base, and the focusing lens and the CMOS base are arranged on the optical focusing lens. The focusing lens is arranged at the bottom of the image intensifier, and the CMOS base is arranged at the bottom of the image intensifier. According to the utility model, through the sizes of imaging visual angles of a plurality of CMOS, the light inlet amount of the aperture, and the adoption of the CMOS of the same specification when a plurality of cameras are used for image acquisition, when image fusion is carried out, the image size and the data flow size can be unified, the fused image does not deviate, the difficulty of later software algorithm repair is reduced, the image quality is improved, and the image noise is reduced; meanwhile, the light incoming amount, the imaging focal length and the image size of the CMOS needing image fusion are unified, and image fusion can be more accurate.

The invention discloses a high-adhesion anode fluorescent screen and a manufacturing method thereof, and relates to the technical field of low-light-level image intensifier core component manufacturing, the high-adhesion anode fluorescent screen comprises a fluorescent screen, the fluorescent screen is made of glass or a sapphire substrate, the fluorescent screen is provided with a micropore array structure, the micropore array structure comprises a plurality of micropores arranged in an array, the aperture of each micropore is 5-10 [mu] m, and the diameter of each micropore is 5-10 [mu] m. The hole depth is 3-5 microns, the hole pitch is 1-2 microns, fluorescent powder is filled in each micropore, and the fluorescent powder is made of P43 or P45 fluorescent powder. According to the invention, the micropore array can form an anchoring structure, the fluorescent powder slurry is coated, the holes are filled with the particles and the binder, and the fluorescent powder layer and the substrate are locked; the stripping tendency of the fluorescent powder layer caused by thermal expansion and cold contraction, vibration or external stress is resisted through geometric constraint, and interaction force is generated with internal stress of the fluorescent powder layer, so that adhesion is enhanced; a narrow-band efficient fluorescent material is selected to cooperate with the micropore light regulation effect, the efficient light-emitting characteristic of the fluorescent powder is enhanced, a mature manufacturing process combination is combined, and breakthrough improvement of the performance of the fluorescent screen is achieved.

The application discloses a device and method for testing the light feedback characteristic of a low-light image intensifier image tube, which comprises a light source, a neutral filter box, an adjustable aperture diaphragm, an integrating sphere, an illuminometer, a contrast test target plate, a conjugate projection lens assembly, an image tube, an industrial camera, an image tube high-voltage power supply, a computer and a test dark box. The method tests the linearity of a certain fixed spatial frequency line under the corresponding MCP voltage of the image tube, and obtains the MCP voltage of the image tube at which the light feedback occurs according to the change of the contrast of the image tube with the MCP voltage. If the brightness gain corresponding to the voltage is higher than the required brightness gain, the image tube does not have the risk of light feedback, otherwise, the image tube has the risk of light feedback. Whether the image tube and the high-voltage power supply packaged as an image intensifier have the risk of light feedback is determined. The application realizes the accurate test of the light feedback characteristic of the low-light image tube, can avoid the circulation of the image tube with the risk of light feedback, and guarantees the imaging quality of the low-light image intensifier.

The application provides a detection system and method for early extremely weak flame imaging positioning, which comprises a horizontal light path branch, a vertical light path branch and a video circuit processing board; the horizontal light path branch is coaxially connected with a first focusing lens, a light splitting prism, an ultraviolet filter, a second focusing lens, an image intensifier and a first image detector in sequence along a horizontal direction; the vertical light path branch is connected with a third focusing lens and a second image detector in sequence along a direction perpendicular to the horizontal light path and a light splitting surface of the light splitting prism; the video circuit processing board is provided with a video circuit processing board, which is electrically connected with the first image detector and the second image detector respectively to receive image electric signals output by the two detectors. The system can image and detect early extremely weak flames at a very long distance, can amplify the spectrum of the flame alone at a high magnification, and cannot amplify the spectrum of other background objects, so that the characteristics of the flame are highlighted.

The utility model discloses a dual-channel low-light night vision device, which comprises a lens body group, a low-light lens group arranged at the front end of the lens body group, an eyepiece group arranged at the rear end of the lens body group, and a white-light lens group, the mirror body set comprises a mirror body shell, an image intensifier installed in the mirror body shell, a controller installed on the mirror body shell, a battery, an infrared light supplementing lamp, a photosensitive lamp and a switch. The controller is electrically connected with the image intensifier, the battery, the infrared light supplement lamp, the photosensitive lamp and the switch. The white-light lens group is mounted at the front end of the lens body group, and the optical axis of the white-light lens group is parallel to the optical axis of the low-light lens group; an image combination prism group used for overlapping the optical axis of the white light lens group and the optical axis of the low-light lens group is mounted in the lens body shell; the image combination prism group comprises an upper beam splitter prism and a lower beam splitter prism which are used for changing the optical axis of the low-light-level mirror group. The LED lamp has the advantage of being capable of being used in both low-illumination and strong-light environments.

The application discloses a kind of molecular marker velocity measurement methods for steady flow field under high-speed wind tunnel, belong to wind tunnel test technical field.To solve the problem of improving the robustness and precision of MTV data processing.The present application includes based on femtosecond laser system in the upper part of test section to the directly below incidence wavelength femtosecond pulse laser generates fluorescent bright line, after flow field stabilizes, trigger image intensifier, using camera to collect test image;Collect the fluorescent bright line reference image under the condition of no wind, as calibration image, place steel plate ruler in the fluorescent bright line plane, calculate space and pixel conversion coefficient;Image correction is carried out to test image, and the test image after rotation correction is obtained using fast fourier transform method, calculate pixel displacement;Using space and pixel conversion coefficient and pixel displacement, conversion is carried out to obtain actual velocity in space.The present application can significantly reduce the quality requirement of test image.

With the invention, the afterglow of a fluorophore can be visualized by observation with a rolling-shutter camera under pulsed illumination. Image sections captured during a dark phase contain only the light emitted by long-lived fluorophores. This enables the imaging acquisition of long-lived fluorescence using inexpensive, widely available CMOS cameras without moving parts and without image intensifiers and without synchronization of camera and pulsed illumination.

The invention discloses a high-precision coupling and centering device for an image intensifier and a detector. The high-precision coupling and centering device comprises a detector pose adjusting module and an image intensifier pose adjusting module, the detector pose adjustment module is nested in the image intensifier pose adjustment module, and the detector pose adjustment module is used for driving a detector to perform Rx1, Ry1, Rz1 and Z-axis dimension adjustment; and the image intensifier pose adjusting module is used for driving the image intensifier to carry out Rx2, Ry2, Rz2, X-axis, Y-axis and Z-axis dimension adjustment relative to the detector pose adjusting module in the image intensifier, so that the image intensifier and the detector are coupled and centered. The independent pose adjustment of the detector and the image intensifier can be realized by using the detector pose adjustment module and the image intensifier pose adjustment module, and the detector and the image intensifier are relatively moved and attached under the condition of ensuring that the detector and the image intensifier are centered, so that high-precision coupling is realized.

Vision system (300) for amplifying and segmenting an image (100) of an environmental scene, comprising the following: an image amplifier (305) which amplifies a segmented image of the surrounding scene incident on an input of the image amplifier and provides an amplified and segmented image of the surrounding scene to an observer at an output of the image amplifier; and an input-side optical module (301) comprising at least two optical imaging means (302, 303, 304) that generate the segmented image of the surrounding scene and map it to the input of the image intensifier, wherein a first optical imaging means of the at least two optical imaging means generates a first image segment (102) of the surrounding scene with a first image scale, and, wherein a second optical imaging means of the at least two optical imaging means generates a second image segment (101) of the surrounding scene with a second image scale.

The invention relates to the technical field of image intensifiers, and particularly discloses an audio noise suppression device and method for an automatic gating type image intensifier, and the device comprises a voltage stabilization power supply circuit module, a microprocessor, a low-voltage pulse circuit module, a gating gate circuit module, and a cathode output circuit module. The input end of the voltage-stabilizing power supply circuit module is connected with a 2-4VDC power supply, and the output end of the voltage-stabilizing power supply circuit module outputs 3.3 VDC power supply voltage and is connected with a power supply input pin and a grounding pin of the microprocessor; a PWM output pin of the microprocessor is connected with an input signal end of the low-voltage pulse circuit module; the signal output end of the low-voltage pulse circuit module is connected with the control input end of the gating gate circuit module; the high-voltage power supply input end of the gating gate circuit module is connected with high-voltage alternating current, and the high-voltage pulse signal output end of the gating gate circuit module is connected with the input end of the cathode output circuit module; and the output end of the cathode output circuit module is connected with the photoelectric cathode of the image intensifier single tube.

The utility model discloses a structure enabling a detector to freely limit power supply, which relates to the technical field of detector accessories and comprises a night vision device assembly and an instrument rack, a movable seat is movably connected onto the instrument rack, and a lens cone is fixed on the movable seat through a screw; and the power limiting assembly is arranged on the instrument rack and the movable seat and comprises a magnetic block embedded in the movable seat, an inductive switch is embedded in the instrument rack, and an adjusting switch is arranged on the instrument rack. The beneficial effects of the utility model are that through the arrangement of the power limiting assembly, when the lens cone is vertical downwards, the magnetic block and the inductive switch are arranged in a staggered manner, a circuit where an image intensifier in the night vision device assembly is located is in a connected state and maintains normal opening, and normal use of the night vision device assembly is ensured; the circuit where the image intensifier is located in the night vision device assembly is in a disconnected state, rollover power failure is maintained, and actual use requirements are met.

The invention relates to a synchronous observation system and an analysis method for an atomization field and a combustion field of a liquid propellant, and solves the problems of difficulty in synchronous shooting frequency division and high synchronous time precision requirement in the existing visual observation technology. An atomization shooting unit is arranged on a transmission light path of a semi-transparent semi-reflective mirror, images of an atomization field and a combustion field are obtained at the same time at the same shooting angle, and a clock delay pulse signal generator serves as an external clock to control the time sequence of a first high-speed camera, an image intensifier and a second high-speed camera at the same time. The delay pulse signal generator serves as an external trigger and simultaneously controls shooting starting time of the first high-speed camera and the second high-speed camera, so that the first high-speed camera and the second high-speed camera are started synchronously.

The invention discloses a low-light-level image intensifier filling and sealing structure and a filling and sealing method, and belongs to the technical field of image intensifiers. According to the encapsulation method, a pressure glue injection vacuum encapsulation technical scheme is generally adopted, and a base, an upper sealing ring, a sealing ring, a lower sealing ring and an image intensifier encapsulation shell in the encapsulation structure form a sealed cavity. In vacuum encapsulation equipment, the encapsulation glue is injected from a bottom glue injection head and enters the image intensifier from the bottom of an image intensifier encapsulation shell and a waist glue inlet hole respectively, air in the image intensifier is exhausted from bottom to top, the encapsulation glue finally overflows from a glue outlet hole of an image intensifier encapsulation cover, and complete filling of glue in the image intensifier is achieved. Compared with a traditional immersion vacuum potting method, on the premise that the same potting quality is guaranteed, the using amount of the potting adhesive is greatly reduced, the production cost is reduced, meanwhile, the designed potting structure is easy to assemble and disassemble, and the large-scale production efficiency is effectively improved.

The utility model relates to the technical field of coal mine exploration, in particular to an in-hole television peeping device integrating low-light night vision and panoramic drilling camera shooting. The device is composed of a camera system, a low-light night vision device, a variable-diameter flange plate and a probe rod. The camera system comprises a shell, a CCD optical sensor, a camera lens, a light source and a conical reflector; the low-light night vision device comprises an objective lens system, an image intensifier, a power supply and an eyepiece system. Light emitted by the light source is reflected by the inner wall of an exploratory hole, is sequentially enhanced by the objective lens system and the image intensifier and then is transmitted to the conical reflector through the eyepiece system, and finally, a panoramic drilling image is generated by the CCD optical sensor. By combining the low-light night vision technology and the panoramic imaging technology, the image quality under the low-light condition is remarkably improved, and the recognition precision of the hole wall geologic features is improved. The device is simple in structure and low in cost, has remarkable economical efficiency and practicability, and provides an innovative solution with high cost performance for the field of coal mine exploration.

A photodetector capable of accurately and easily positioning a sample at the focal position of a predetermined measuring light beam is provided. [Solution] The light detection device 1A includes an image intensifier I, a case 2 that supports the image intensifier I, and an attachment mechanism 9 that is configured to allow a holding structure 50 for holding the case 2 to be detachably attached. The attachment mechanism 9 is arranged so that, in an attached state where the holding structure 50 is attached to the attachment mechanism 9, the holding structure 50 indicates the target position at which light incident on the image intensifier I should be focused.