Abstract: A multi-cavity optical device allowing selective control of a bandpass characteristic thereof . Fabry-Perot structures are coherently coupled together to form a narrow bandpass structure. At least one of the spacer regions in the device includes an active material that changes the optical thickness of the spacer to de-tune the device. In one embodiment, the active material is transparent and lies along the optical path through the device. In another embodiment, an active material that lies outside of the optical path tunes an air gap. Altering the first or last spacer in a multi-cavity structure provides variation in the transmission loss while generally retaining a flattop filter response with low passband ripple. Altering interior spacer regions provides high sensitivity to variations in the optical thickness of the spacer.

Abstract: The absorption of a spacer material in a Fabry-Perot type structure is changed to achieve an optical switching function. In one embodiment, the spacer material is a semiconductor material and an electronic control signal changes the Fabry-Perot between a transmissive state and a reflective state. In the reflective state, the device operates as a switch can be modeled as a mirror on a substrate of quasi-infinite thickness. In a further embodiment, a wavelength-selective optical component is placed between the input of the switch and the Fabry-Perot structure to improve the spectral response of the switch.

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.

Abstract: A leak-corrected linearly variable filter comprises optical filter coatings formed on an assembly of one or more optically transmissive substrates. Leaks due to the longitudinal precession of incident light within the substrates are suppressed by forming the filter such that no two surfaces which are reflected at the same wavelength within the range of interest are parallel. Typically, the constituent substrates of the filter are oriented at a slight angle relative to one another and filter coatings having overlapping reflective wavelengths are deposited on different substrates rather than on the two parallel sides of the same substrate. Alternatively, venetian shade structures can be incorporated within the substrates to block longitudinal precession of light.