The innovation of this paper is combining the micro-nano optical technology and the vacuum photoelectric imaging devices manufacturing. The multialkali photocathode deposition substrate is designed with a meta-surface structure by using the Finite-difference time-domain. According to the nanoimprinting and the atomic layer deposition, the structure of meta-surface can be obtained. Metasurface have the ability of simultaneously controlling the phase of the light by tailoring the geometry of microstructures. The negative loss in the direction of light wave propagation is suppressed, the reflection at the interface between the cathode and the deposited substrate is reduced, and the absorption coefficient of the cathode material to the incoming light is improved. And the absorption rate of the incident light can be increased by 20.5%. The atomic layer deposition is used to prepare the nanolaminate on the surface of the micro-structure. Based on the imaging tube with the meta-surface, the experiment results show that the average value of the quantum efficiency increased by 21.2% in the visible light range and increased by 10.3% in near infrared band respectively, which reaching the international advanced level. A new method is provided to improve the performance parameters of the vacuum photoelectric imaging devices and point the direction for the improvement of the imaging tube. As shown in this paper, the performance parameters of the vacuum photoelectric imaging devices still have great development potential by optimizing the structure of the meta-surface.
We developed an UV Solar Blind image intensifiers with 18mm diameter semi-transparent cesium telluride photocathodes in a close proximity focus microchannel plates (MCP) tube. Cs-Te photocathodes have been evaporated onto quartz substrates at an elevated temperature to achieve quantum efficiency (QE) up to 34% and 70mA/W at 254nm, low dark current, low out of band response and high stability. New Cs-Te photocathodes have been fabricated for image intensifiers upgrade, which show fine image resolution, and less variation in high electron gain of the MCP. With these improvements, the image intensifier tube with new Cs-Te photocathodes will expand the application fields in low-light level UV Solar Blind detection.
Image intensifiers have been wildly used for military, law enforcement and commercial applications. Its small size, weight and power (SWaP) make it ideal for integration into different systems. Normally, the performance of image intensifiers is measured at room temperature, but it is expected to operate in vary temperature environments. Therefore, it is very important to know the variation of the image intensifiers performance with temperature. Here, we characterize the variation of intensifier photocathode, microchannel plates (MCPs) and phosphor screen over a large range of temperatures. The “bare” tube is connected to high voltage power supplies via cables. The power supplies and all measuring instruments are outside the chamber in order to avoid the influence of temperature. The result could be used to optimize and control the luminance gain of image intensifiers.
In this paper, the influence of the microchannel plates (MCP) opening area ratio (OAR) and secondary electron emission (SEE) coefficient of SEE layer on the noise factor of image intensifier tube have been studied. According to the experiment, the influence percentage of MCP OAR and SEE coefficient of MCP SEE layer on noise factor reduction has been obtained. A MgO SEE layer with SEE coefficient of 4.5 was coated on the MCP input side with an OAR of 68%. After being assembled as an image intensifier, the noise factor of MCP decreases from 1.638 to 1.096, and drop 33.0%, which laid a good foundation for improving the signal-to-noise ratio of image intensifier.
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