Abstract: A thermally stabilized optical filter device includes a multilayer optical bandpass filter on a transparent substrate, with the transparent substrate being composed of a material having a first coefficient of thermal expansion. An encasement surrounds the transparent substrate such that the bandpass filter is exposed for transmission of predetermined optical wavelengths there through. The encasement is composed of a material having a second coefficient of thermal expansion that is different than the first coefficient of thermal expansion. The encasement provides thermal stability to the optical properties of the bandpass filter by compensating for changes in the filter that occur with temperature variations. In another embodiment, a collet assembly provides means for selectively compressing a filter chip to tune the filter response.

Abstract: A thermally stabilized optical filter device includes a multilayer optical bandpass filter on a transparent substrate, with the transparent substrate being composed of a material having a first coefficient of thermal expansion. An encasement surrounds the transparent substrate such that the bandpass filter is exposed for transmission of predetermined optical wavelengths there through. The encasement is composed of a material having a second coefficient of thermal expansion that is different than the first coefficient of thermal expansion. The encasement provides thermal stability to the optical properties of the bandpass filter by compensating for changes in the filter that occur with temperature variations. In another embodiment, a collet assembly provides means for selectively compressing a filter chip to tune the filter response.

Abstract: The present invention discloses a bonding collar for coupling optical components and methods for manufacturing the bonding collar and mounting the optical components to the bonding collar. The bonding collar is composed of a material having a thermal expansion coefficient comparable to that of the coupled optical components and is formed by a first socket into one end of a cylindrical blank and a square second socket in communication with the first socket so that when a GRIN lens is inserted in the first socket and a filter is placed in the second socket, the GRIN lens and filter will directly contact each other. Further, the manufacturing process ensures alignment between the two sockets. The filter and GRIN lens are bonded to the bonding collar by applying adhesive to the visible interfaces that the bonding collar forms with the GRIN lens and the filter.

Abstract: A process suitable for forming multi-layer (up to at least several hundred layers) monotonic/linear variable/wedge filter coatings on a single substrate surface and for forming monolithic filter assemblies which incorporate such filters, is disclosed along with the designs for such filters. The monolithic process uses radially variable filter fabrication techniques in combination with ion-assisted deposition to form stress controlled, radially variable filter coatings of the desired varied optical profile, preferably using high and low index materials stich as tantala and silica. Stress is minimized by balancing the amount of ion assist and the coating rate. Slices are cut radially from the substrate to form quasi-linear variable filters. Other coatings such as, but not limited to, a wide band hot mirror can be formed on the opposite surface of the substrate from the radially variable LVF method.