US 6,982,818 B2
Electronically tunable optical filtering modules
Nabeel Agha Riza, Oviedo, Fla. (US); and Muhammad Junaid Mughal, Orlando, Fla. (US)
Assigned to Nuonics, Inc., Winter Park, Fla. (US)
Filed on Oct. 10, 2003, as Appl. No. 10/684,260.
Claims priority of provisional application 60/450049, filed on Feb. 27, 2003.
Claims priority of provisional application 60/417413, filed on Oct. 10, 2002.
Prior Publication US 2004/0109232 A1, Jun. 10, 2004
Int. Cl. G02F 1/00 (2006.01); G01J 5/02 (2006.01)
U.S. Cl. 359—237 18 Claims
OG exemplary drawing
 
1. A method of equalizing light propagation differences in at least two spaced optical beam pathways in a polarization medium comprising:
splitting an optical beam emitted from an emission point to produce a first beam portion and a second beam portion;
directing the first optical beam portion in a forward direction in a first optical pathway, and redirecting the first optical beam portion in a reverse direction in a second optical pathway;
directing the second optical beam portion in a forward direction in the second optical pathway, and redirecting the second optical beam portion in a reverse direction in the first optical pathway;
disposing an electronically variable polarization control device in at least one of the first pathway and the second pathway for processing the first beam portion and the second beam portion passing therethrough; and
recombining the first optical beam portion traveling in the reverse direction along the second optical pathway and the second optical beam portion traveling in the reverse direction along the first optical pathway into a processed optical beam directed back into the emission point so that each of the optical beam portions traverses the same path from the emission point back into the emission point.