Large size optical windows for superfluid helium applications

摘要

We report on a technique to seal large size optical windows on metal cryostats for He II applications. The sealing of optical windows on metal cryostats for superfluid helium applications has always been challenging due to the different thermal expansion coefficients of the component materials: glass (such as fused silica or sapphire), the metal flange that the glass sits on, and the bolts used to hold the glass in place.