Image intensifier for improving detection performance of low-light level imaging system at normal temperature

Abstract

The invention discloses an image enhancer for improving the detection performance of a low-light-level imaging system at normal temperature. The image enhancer comprises a photocathode and a microchannel plate which are arranged oppositely, a front electrostatic focusing electron optical system and a rear electrostatic focusing electron optical system which are sequentially arranged from the photocathode to the microchannel plate between the photocathode and the microchannel plate; a fluorescent screen which is arranged outside the microchannel plate, and a magnetic mirror array device which is arranged between the front electrostatic focusing electron optical system and the rear electrostatic focusing electron optical system. The image enhancer expands the effective utilization of low-light-level electron, reduces the escape probability of emergent electron at the photocathode in a magnetic mirror, more effectively accumulates optoelectronic signals at normal temperature and achievesthe enhancement to extremely weak light signals, thus achieving clear imaging at the illumination intensity of 10<-8>lx.

Description

technical field [0001] The invention belongs to the technical field of low-light imaging detection, and relates to an image intensifier for improving the detection performance of a low-light imaging system at normal temperature. Background technique [0002] Low-light night vision technology is widely used in transportation, television, communications, medicine and health, military and other fields. After nearly 30 years of rapid development, a detection limit of 10 has been developed -9 CCD (charge coupled device) camera with lx illuminance, German B&M Spectrum Company increased the detection limit of CCD camera to 10 at the temperature of -150°C -11 lx. Low-temperature low-light detection devices have a high signal-to-noise ratio, but they are bulky, technically difficult, and expensive, resulting in very limited application fields. Therefore, it is more practical to increase the detection limit of low-light imaging systems at room temperature. [0003] Our country has ...

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Problems solved by technology

[0004] However, in order to achieve a higher low-light detection limit at room temperature, it is necessary to solve the problem of how to accumulate photon signals for a long time under low-light conditions.

At present, various low-light detection devices used, such as image-intensified ICCD (Intensified Charge Coupled Devices) and electron multiplied EMCCD (Electron Multiplying CCD), etc., although they each use different optical signal enhancement methods, but the optical signal However, the accumulation is completed through the long-term integration of the CCD. During this process, many factors such as thermal noise and bright light at the corners seriously affect the imaging quality. Therefore, the performance of the CCD directly limits the improvement of the low-light detection limit.

[0005] Although the various devices researched and developed above have the effect of strengthening and multiplying the electrons generated by the image intensifier, they have not been able to effectively accumulate the electrons, but only accumulate the photon signals for a long time through the CCD. Therefore, The low-light detection limit is largely limited by the 10 -6 lx increased to 10 -8 lx

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