SBIR-STTR Award

Several concepts for integrated optic polarization beamsplitters have been proposed. However, for any integratedoptic design, achieving 30 dB extinction requires a fine tuning mechanism for the coupler. We propose a novel method, using proton exchange and titanium diffusion in lithium niobate, tofine tune a polarization separating coupler. The technique allowsmodifying the transfer length for one polarization while leavingthe other polarization transfer length unaltered. In Phase 1, wewill demonstrate the viability of this concept. Ramar Corporationis uniquely positioned to achieve rapid commercialization of suchdevices since we have been in this business for five years, wehave an existing customer base for such devices and we arecurrently solving the packaging issues that will be extremelyrelevant to this effort.Commercial Applications:IO polarization beamsplitters areessential for polarization diversity coherent detection. Theywill also find use in sensor concepts that use polarization statefor information encoding. they will complement in-line fibercomponents such as isolators.

Several concepts for integrated optic polarization beamsplitters have been proposed. However, for any guided wavedesign achieving high extinction ratio requires a fine tuning mechanism for the coupler. In the Phase I work we demonstrated couplers with 20 dB extinction for both polarizations using a novel dual diffusion technique using titanium guides in lithiumniobate. The technique allows modifying the transfer length for one polarization while leasing the other polarization transfer length relatively unaltered.In Phase II we will combine high extinction ratio with low fibercoupling loss to achieve polarization beamsplitters with 20 dBextinction and fiber to fiber insertion loss less than 2 dB. .RAMAR CORP is antiquely positioned to achieve rapidcommercialization of such devices since we have been in thisbusiness for six years, we have an existing customer base forthese devices and we are currently solving the packaging issuesthat will be extremely relevant to this effort.Potential commercial applications of the research:IOpolarization beamsplitters are essential for polarization diversity coherent detection. They will also find use in sensor concepts that use polarization state for information coding. They will complement in-line fiber components such as isolators.