US 7,009,680 B2 · Narrow band tunable filter with integrated detector

Abstract

A polarization insensitive narrowband tunable filter utilizes an active liquid crystal cell to change the index of refraction and tuning of a waveguide resonant filter employing a nanostructured waveguide grating and polarization beam splitters to independently channel and convert S- and P-polarization states into optically and geometrically parallel beams which pass through the device. A multi-pixel configuration offers extended tuning range by employing a 1×N optical switch or splitter and N tunable pixel-filters each having offset center frequency enabling the tuning range of one pixel to partially overlap another pixel rendering the device and 1×N switch or splitter capable of scanning pixels to yield an expanded continuous tuning range mode. Optional features of the present invention include deposited photodetectors, deposited metal gasket moisture barrier, deposited spacer layer with high cell gap tolerance, a deposited thermal sensor and heater and related temperature compensation control schemes.

Claims23

Dependent claims

A polarization independent tunable filter comprising:

a liquid crystal cell comprised of a first and second substrate, said first substrate includes a first surface having a rotating mirror and a second surface including a polarization beam splitter and waveguide resonant grating filter, said second substrate having a second surface including a rotating mirror and a first surface having a polarization beam splitter, said substrates being mutually disposed such that the second surface of the first substrate faces the first surface of the second substrate.

Dependencies are inferred from the claim text.

Narrow band tunable filter with integrated detector

Life of this patent

Narrow band tunable filter with integrated detector

Life of this patent

Abstract

Claims23