Mono Silicon Wafer for LWIR Applications
The long wave infrared (LWIR) band, whose wavelength range is consistent with the peak blackbody radiation wavelength of near room temperature objects, is crucial for a wide range of imaging applications such as night vision, remote sensing, robotics, industrial process monitoring, building inspection, automotive sensing, and gas detection. However, due to phonon absorption, most classical optical materials, such as oxide glasses and polymers, are not transparent in the LWIR band. Therefore, traditional LWIR optical devices have to rely on special alternative materials, such as germanium and sulfur based glass. But germanium is expensive to manufacture, while sulfur based glass is mechanically fragile. In addition, classical refractive optical devices made from these materials, especially germanium, are temperature sensitive and prone to thermal optical focal length drift. To address the issue of LWIR band materials, silicon has become one of the highly anticipated solutions due to its unique properties. PAM-XIAMEN is able to offer mono silicon wafer for LWIR applications, taking the following specification for example:
1. Mono Silicon Wafer for LWIR Applications
| Item | Silicon wafer |
| Size | 6, 8 inch |
| Orientation | <100>, <111> |
| Doping | P-Type (Boron) |
| Resistivity | 1~10 ohm·cm |
| Surface Finished | Double-side polished |
| TTV | ≤5um |
| Warp | ≤40um |
| Bow | ≤40um |
| Flat/Notch | SEMI Standard |
| Package | Vacuum Packing |
2. Si based Metalens for LWIR Imaging System
Silicon wafers, due to their thin and lightweight nature, can significantly reduce the volume and weight of imaging systems, improving portability; Mature microfabrication techniques, such as photolithography and deep reactive ion etching (DRIE), make it easy to process and capable of producing fine microstructures to achieve complex optical functions; Meanwhile, as a cheap and easily accessible material, monosilicon wafer helps to reduce system costs.
Currently, a research team is focusing on exploring the feasibility of using silicon wafers as a platform to construct high-performance long wave infrared (LWIR) imaging systems. They have proposed and implemented a solution based on metasurface technology, specifically designing and manufacturing a metasurface lens with a numerical aperture (NA) of 0.45 and a diameter of 2cm based on lightly doped silicon substrate. The imaging performance of the silicon lens under different temperature environments was verified through systematic simulation and experiments. The results indicate that even if there is chromatic aberration in the lens, it can still effectively image under ambient light.
Study has shown that silicon metasurface technology has opened up a new technological path for miniaturization and lightweighting of LWIR imaging systems, and the all silicon metasurface lens has imaging capability under environmental thermal radiation, and color difference is not a decisive obstacle. This technology is expected to be applied in multiple fields such as wearable thermal imaging devices, autonomous drone monitoring, and satellite imaging in the future.
Whether you need silicon wafers for research or for industrial applications, please contact us email at [email protected] and [email protected].