Sapphire lenses are excellent optical lenses with good transmittance in ultraviolet, infrared, and visible light bands. They can meet the requirements of multi-mode composite guidance. Sapphire filters have excellent mechanical and chemical stability, high temperature resistance, high strength and hardness, and can meet the harsh requirements of transmissive-windows for hypersonic missiles.
A sapphire lens is an ideal material for multi-spectral wide-band windows. Compared with ordinary wide-band window materials, it has many excellent mechanical and optical properties and is suitable for laser instruments, optoelectronic devices, and window materials. SiO2 thin films were prepared on sapphire substrates by sputtering, and the infrared transmittance of the sapphire samples before and after coating was tested. The infrared transmittance performance of the coated and uncoated sapphire samples was tested and analyzed after high temperature and rain erosion, and the results showed that the infrared transmittance of the sapphire substrate was significantly improved after the SiO2 film was coated on it.
At high temperatures, SiO2 thin films still have good antireflection properties, and the average transmittance of the coated sapphire samples is significantly higher than that of the uncoated sapphire samples. After rain erosion testing, the average transmittance loss of the coated sapphire samples is very small, and the infrared transmittance of the coated sapphire is significantly higher than that of the uncoated sapphire.
Sapphire lenses have been widely used in civil fields, such as medical instruments, environmental protection equipment, laser equipment, chemical equipment, high vacuum testing equipment, and fiber optic spinning plates in the textile industry. They are also used as scanning windows for barcode scanners, and watch crystals in watches. Sapphire monocrystalline tubes can be made into many metal gas discharge lamps, which not only obtain satisfactory results, but also can work continuously without cooling. The application scope of sapphire monocrystalline tubes in the field of electro-optical sources is also becoming more and more extensive.
For military applications, no industry needs reliable and durable materials more than the military, so it is not surprising that the demand for sapphire lenses is large. Sapphire can maintain its characteristics under high pressure, high temperature, acidity, high impact forces, and almost any other situation you can imagine. This makes sapphire an ideal choice for protecting important optical devices and lasers. Both military and commercial aircraft, ground and water transportation vehicles use sapphire to protect visual systems, sensors, cameras, and lasers. Submarines also use sapphire because of its high pressure and saltwater resistance.
In medical applications, sapphire lenses are widely used. One of the most common medical applications is in the endoscope market. Endo comes from the Greek word "internal," while scopy comes from the Greek word "viewing" or "observation." Endoscopes contain small cameras and are introduced into the patient's body so that doctors can perform surgery, diagnosis, and observation. Sapphire lenses are used to protect endoscopic instruments because they are scratch-resistant, easy to clean and disinfect, and chemically inert. More importantly, they can be used for many years without replacement.