Skip to Content
Find More Like This
Return to Search

Wideband dichroic-filter design for LED-phosphor beam-combining

United States Patent

December 28, 2010
View the Complete Patent at the US Patent & Trademark Office
A general method is disclosed of designing two-component dichroic short-pass filters operable for incidence angle distributions over the range, and specific preferred embodiments are listed. The method is based on computer optimization algorithms for an N-layer design, specifically the N-dimensional conjugate-gradient minimization of a merit function based on difference from a target transmission spectrum, as well as subsequent cycles of needle synthesis for increasing N. A key feature of the method is the initial filter design, upon which the algorithm proceeds to iterate successive design candidates with smaller merit functions. This initial design, with high-index material H and low-index L, is (0.75 H, 0.5 L, 0.75 H)^m, denoting m (20-30) repetitions of a three-layer motif, giving rise to a filter with N=2 m+1.
Falicoff; Waqidi (Stevenson Ranch, CA)
Light Prescriptions Innovators, LLC (Altadena, CA)
11/ 982,492
November 2, 2007
STATEMENT REGARDING FEDERALLY FUNDED RESEARCH AND DEVELOPMENT This invention was supported in part by the National Energy Technology Laboratory Award No. DE-FC26-05NT42341. The Government may have certain rights in this invention.