Compact external grating pbs/pbc coupler

Abstract

Approaches to Compact External Grating PBS/PBC Coupling are described according to embodiments of the present invention. In one embodiment, a YVO4 crystal is used to split a beam or combine multiple beams into a single beam. A lens is used to convert a mode of the light to match a mode of a grating port. A glass wedge is designed to bend the light from horizontal to a nearly vertical orientation to match an exit angle of a grating port. When a source or a receiver utilizes an optical fiber, a fiber holder may be used to bond the fiber to the source or receiver. The PBS/PBC described has much less insertion loss compared to existing 2D grating coupler techniques, and has a wider spectral bandwidth due to flexibility in mode matching compared to existing 2D grating couplers. The PBS/PBC described herein also has a better polarization-extinction ratio than the existing 2D grating couplers, and the horizontal coupling configuration enables a design that is thinner and more compact compared to the near vertical coupling in 2D grating coupling.

Dependencies are inferred from the claim text.