Application of germanium in infrared optics industry

2020-12-07

Application of germanium in infrared optics industry
Metal germanium has excellent infrared optical and physical properties. It is an ideal window, lens and drum material for thermal imaging cameras. It is widely used in reconnaissance and alert night vision and thermal imaging cameras. It has Irreplaceable status. At present, the infrared optics industry has become the largest application market for germanium, accounting for about 42% of the total germanium consumption.
Ge) belongs to rare and scattered metals, and the distribution is scattered. At present, China's germanium metal reserves and output are among the top in the world. As the largest producer of metal germanium, sufficient raw materials have driven the development of China's germanium industry in the field of infrared optics, but the germanium industry is still at the stage of supplying primary materials. With the adjustment of national policies, my country's germanium research and development and application will make leapfrog progress. The in-depth technical cooperation between germanium enterprises will further deepen, and the germanium industry and infrared optics industry will also further develop and grow. Infrared optical properties of germanium materials
With the rapid development of laser and infrared technology, the good properties of semiconductor materials represented by germanium in infrared optics have gradually attracted people's attention.
Infrared optical materials must have the following characteristics:
Wide infrared transmission band;
High transmittance to different wavelengths of infrared;
It has ideal refractive index and low dispersion for different wavelength infrared;
The material has good mechanical and thermal properties and adaptability to the environment;
Easy to process into various shapes and large sizes;
The manufacturing cost is low.
At present, the main infrared optical materials are semiconductor materials germanium and silicon, and III-IV compound semiconductors GaAs (gallium arsenide), GaP (gallium phosphide) and II-III compound semiconductors ZnS (zinc sulfide), ZnSe
(Zinc Selenide) and so on.
In infrared detection systems such as thermal imaging cameras, germanium is the most widely used as windows, lenses, prisms, and filters. Germanium has the highest refractive index and can be easily processed into a lens. It has a good transmittance in the 8-14 μm band (up to 95% after coating); Germanium is corrosion-resistant, hard to deliquesce, and has good mechanical properties. In infrared detection systems, germanium is an irreplaceable material.
Application of germanium materials in infrared optics
In infrared optics, germanium is mainly used to make infrared optical lenses in infrared detection systems and infrared optical windows to protect infrared optical lenses. More than 60% of the middle and low-end infrared optical lenses have lenses made of infrared germanium single crystal materials. In high-end infrared optical systems, half of the optical lenses are germanium single crystals.
Infrared lenses are mainly used in military and civilian applications. The main application areas of military infrared lenses include airborne infrared lenses, shipborne infrared lenses, land-based infrared lenses, vehicle-mounted infrared lenses, infrared gunsight lenses, helmet infrared lenses, and handheld infrared lenses. The main application areas of civil infrared lenses include security, civil vehicles, civil ships, civil aircraft, police and so on. .