Detection device for transmittance and light-transmitting uniformity of fiber-optic imaging element

Fiber-optic imaging element is prepared by the process of drawing, fiber and multifiber-arranging, hot-pressing, twisting or stretching after matching the optical fiber preform and tube. As the core device of low-level-light (LLL) night vision devices and photomultiplier tubes for particle detection, it is widely used in LLL night vision, electronics, aerospace, nuclear diagnosis, high-speed photography, medical and other fields. The fiber-optic imaging element can transmit the image from the input end to the output end by equal ratio, magnification, reduction or inverted 180 degrees. The image quality mainly depends on the light-transmitting efficiency and light distribution uniformity. However, there is no unified measurement standard and method for the transmission efficiency and uniformity of fiber-optic imaging elements in the visible light band, which has led to differences in the evaluation standards for light-transmitting performance and hindered the technological exchange as well as performance improvement of fiber-optic imaging elements. This paper designs a device that accurately measures the transmittance and uniformity of fiber-optic imaging elements in the visible light band. The software part of the device is mainly composed of control system, sensing system and computing system; the hardware part is coaxially mounted by uniform surface light source, fiber-optic imaging element stage and high-precision luminance meter. The light is emitted from the surface light source and enters the CCD through the fiber-optic imaging element, and then the luminance meter receives the luminance data and passes into the computing system. After calculation, the average luminance value of any area can be obtained, which can complete the high-precision detection of overrate and uniformity of fiber-optic imaging element in the visible light wave band. This device was used to detect the transmittance and uniformity of fiber-optic imaging element, and the transmittance in the effective area of the fiber-optic plate (FOP) and the fiber-optic inverter (FOI) were 52.0771% and 43.1644%, respectively. The transmittance uniformity is 5.5729% and 15.3222% respectively. The repeatability of the fiber-optic imaging element transmittance detection device can reach 10(-2). The device improves the detection efficiency and accuracy of the transmittance and uniformity of the fiber-optic imaging element, and has important guiding significance for the improvement of the optical performance of the fiber-optic imaging element.