High Performance Free-Space Photonic Switching Systems for RF Applications

The goal of this effort is to develop high efficiency optical switching systems based on free space switchable gratings. The use of switched gratings as an enabling technology to arbitrarily steer RF modulated optical carriers from 1 to any of N channels or alternatively from among N input to N output channels has several distinct advantages over other photonic switching systems including: 1) low insertion loss; 2) uniform delay for all routes; 3) miniature micro optic packaging; 4) low crosstalk; 5) reduced complexity; and 6) suitability for rugged monolithic packaging. Further, these systems are scalable for large N. Low insertion loss is obtained utilizing high efficiency switchable diffractive elements to effectively steer each input optical carrier to the desired output channel, with switching times in the microsecond regime. The inherent switch purity of the diffractive elements can be augmented with inclusion of a nonlinear noise suppressor. These diffractive switches also have the potential to be low cost systems. The Phase I effort will result in a feasibility demonstration based on modeling and on a 2 x 2 experimental optical switch testbed. The follow-on Phase II effort will produce a larger dimension switch that is miniaturized and monolithically packaged with minimized losses and crosstalk.