SBIR-STTR Award

We propose to build and test two types of polarization interference filter stages to achieve the goal of a ninety-degree full cone angle, field of view. These filter stages will be of different designs that both have the potential to meet this goal. They will have a 45 millimeter diameter clear aperture and a transmission peak full width at half maximum of less that one nanometer at a wavelength of 532 nanometers. The designs and materials chosen for these filters can be scaled up to clear apertures of at least eighty millimeters diameter. The proposed filter stages will be the basic building block for a complete filter system to be built and tested in Phase II.

Benefits:
The technology developed here will form the basis for a laser communication detector system that can benefit free space laser communication systems during fog and precipitation as well as enabling submarine laser communications. The retarder components developed will enhance Meadowlark Optics' line of commercial retarder products, as well as improving the performance of our line of filter products.

Keywords:
Filter, Optical Filter, Polarization Interference Filter, Laser Filter, Polarization

We propose to build a seven-filter array of wavelength selectable wide field Lyot filters. Each filter will have a hexagonal aperture of 100 mm in the largest dimension and the total clear aperture of the array will exceed 390 cm^2. All filters will have a passband full width at half maximum of approximately 0.3 nm at a wavelength of 532 nm and a free spectral range between adjacent passbands greater than 10 nm. We will provide six of these filters under the base contract and the seventh under the option. The seventh filter will have as an added function 3 selectable passband widths of 0.15nm, 0.3 nm and 0.6 nm. Liquid crystal elements accomplish all wavelength selection and passband width selection functions non-mechanically. We will also investigate the use of a high index birefringent crystal under the option to expand the angular field of view in future filters.

Keywords:
Lyot, Polarization, Retarder, Optical Filter, Filter, Liquid Crystal, Polarizer,