- Conventional fiber optic image bundles
Conventional fiber optic imaging bundles are the core components of medical and industrial endoscopic systems, and can also be used in the field of fiber optic sensing. The fiber optic image beam required for medical endoscopes has a small end face diameter (less than 20000 to 30000 pixels), a large numerical aperture (usually 0.8), and requires the image beam itself to be extremely soft, so that it can enter the human body through the tortuous intestines to detect lesions in organs such as the intestine, stomach, lungs, and bladder. The endoscope with this imaging beam can also be used in industry to inspect the interior of boiler pipelines, sand flipping parts, furnace bodies, aircraft and automotive cylinders, gearboxes, and fuel tanks; It can also be used to observe hazardous areas of radioactive contamination, etc. Therefore, this type of image beam is widely used in medical and industrial fields. Figure 5 shows a conventional fiber optic image bundle [11], length: 700 mm, single fiber diameter: 3 mm, pixel: 5 100, resolution: 44 lp/mm, diameter: 1.0 mm, bending radius: ≥ 2 cm. Figure 6 shows a partial photo of an industrial endoscope.
2. Multi channel structured image beam
When it is necessary to integrate images from different directions and regions onto a single image, single channel image transmission technology cannot be achieved. However, flexible multi-channel fiber optic image transmission technology that uses one end to collect multiple images and the other end to integrate multiple images into one image can be achieved, and it can also combine n small images into one large image. Flexible multi-channel fiber optic image bundles are applied in the field of multi-point scanning technology. Moreover, in certain special occasions, it can replace the large array CCD that is currently unsolvable in China. Figure 7 shows a multi-channel structured fiber optic image bundle.
3. High information fiber optic image bundle
Fiber optic image bundles with hundreds of thousands of pixels and a cross-sectional area of tens of square millimeters or more are commonly referred to as large cross-section fiber optic image bundles. In the 1990s, a high-information fiber optic image bundle with large transmission information, large cross-section, clear images, and the ability to couple with television camera systems was successfully developed. The United States, France and other countries apply it to monitor the working status of space rocket engines, optical fiber visual monitoring systems on helicopters, and optical fiber observation systems for checking the aiming effect of missile shooters. In addition, it can also serve as a relay image transmission device for fiber optic telescopic systems. Figure 8 shows a high-information fiber optic image bundle, and Figure 9 shows its application in a telescopic system.
4. As Se Te glass infrared fiber image transmission bundle
The main difference between As Se Te glass infrared fiber optic image bundles and ordinary fiber optic image bundles is the difference in fiber material. It is formed by drawing As, Se, and Te raw materials into optical fibers in a certain proportion, and then combining them to transmit infrared light information in the 2-12 mm wavelength band. According to reports, connecting infrared optical fibers into image beams and infrared thermal image detectors can be used to detect the thermal distribution of objects in strong magnetic fields, hazardous environments, narrow spaces or small holes. It is particularly suitable for detecting and transmitting image information on the focal plane of three-dimensional gyroscopes, and has important applications in infrared simulation, hot air flow wind tunnel tests, and other fields.
5. Line to surface conversion image beam
Line surface conversion image beam refers to an image beam in which one end of the image cross-section is linear, and the other end can be a rectangle, square, or circle in the usual sense. Arrange one end of the fiber optic image bundle in a straight line shape and the other end in a circular shape, known as a circular to straight converter. When using a circular to straight converter in a fax machine, various documents such as telegrams, newspapers, and photos can be directly transmitted in a flat format. The line to surface conversion image beam shown in Figure 10 can also be used as a scanning transmission element for copiers or laser printers.
6. Application of fiber optic image bundles in other fields
In 1998, the National Astronomical Observatory of Japan used a fiber optic image beam as a pupil splitter in a spectrometer to convert the beam shape and focusing ratio, transmitting the image formed by the telescope in the focal plane to the incident slit of the spectrometer, greatly improving the information processing ability and resolution of the spectrometer, as shown in Figure 11. In 2004, Pennsylvania State University and the Center for Space Science in the United States jointly reported the use of fiber optic arrays as devices coupled with lens arrays in terrestrial planetary probes (TPF) to better eliminate light leakage caused by poor alignment of telescope systems and interferometers in TPF.
