Tellurium (Te) is a chemical element with the symbol Te and atomic number 52. It is a dense, silvery-white metal that is chemically similar to selenium and sulfur. It is widely used as a material in the production of alloys, and as a component of some electronic devices.
In the field of photonics, tellurium crystals are known for their excellent optical properties and are used as optical components such as lenses and mirrors in various applications, including spectroscopy, laser systems, and imaging systems. They are also used in the manufacture of x-ray targets and infrared windows.
One important property of tellurium crystals is their high refractive index, which makes them useful in the manufacture of anti-reflection coatings. They also have low thermal expansion, making them ideal for use in high-temperature applications. In addition, they are durable and resistant to attack by chemical reagents, making them well suited for use in harsh environments.