Yamamura Photonics is developing TO-Cap that uses CaF2, which has excellent transmittance from ultraviolet to infrared (~ 9 μm), as window materials.
Generally, it is difficult to join CaF2 and metals with sealing glass because of the large difference in the coefficient of thermal expansion. However, we actualize to join CaF2 and metal cans by using the resin material named "hybrid material". The "hybrid material" was developed by our parent company Nihon Yamamura Glass as the joining material. In the caps with the "hybrid material", the residual stress due to the difference in expansion coefficient is absorbed by the flexible bonding layer. Therefore, CaF2 and metal cans can be joined, maintaining a certain hermeticity.
CaF2 has good optical properties with a transmittance of 90% or more over a wide range from ultraviolet to infrared without optical coating. Therefore, cost reduction is expected compared to caps for mid-infrared wavelength region (4-9 μm) applications that use Ge with optical coating as window parts.
PRODUCTS
PRODUCTS UNDER DEVELOPMENT
Products Under Development
CaF2 Cap
OUTLINE
Specifications under development
Size: TO-5, TO-8, etc.
Window Material:CaF2(Single crystal)
Shell Material: Kovar, SUS, etc.
Hermeticity:Around 1×10-8Pa・m3/s
Transmittance: T> 90% @ ~ 9μm (Non-Coating)
Heat resistant Temperature: 250℃ (in the air)