FABRICATION OF NARROW-BAND THIN-FILM OPTICAL FILTERS

摘要

A multi-layer thin-film narrow-band filter (50) is fabricated by a process wherein each half (30, 40) of a symmetric stack is deposited under exact conditions, either successively or contemporaneously. The two halves (30, 40) of the filter structure are then combined and bonded together using a wet bonding process that remains reversible for a period of time sufficient for testing the filter and, if necessary, for separating the two halves to regain access to the spacer layer. Accordingly, the spacer layer (38, 48) may be adjusted to shift the peak wavelength, if necessary, to the precise design specifications for a particular application. After correction, the components (30, 40) of the symmetric filter are bonded again using the same wet process.