Integrated MEMS switches for selectively coupling light in and out of a waveguide
A steerable optical transmit and receive terminal includes a MEMS-based N×1 optical switch network. Each optical switch in the optical switch network uses an electrostatic MEMS structure to selectively position a translatable optical grating close to or far from an optical waveguide. In the close (“ON”) position, light couples between the translatable optical grating and the optical waveguide, whereas in the far (“OFF”) position, no appreciable light couples between the translatable optical grating and the optical waveguide. The translatable optical grating is disposed at or near a surface of the optical switch network. Thus, the translatable optical grating emits light into, or receives light from, free space. The steerable optical transmit and receive terminal also includes a lens and can steer a free space optical beam in a direction determined by which port of the N×1 optical switch network is ON.
1. An optical switch network, comprising:
a common input/output port;
a waveguide having a length and being optically coupled to the common input/output port; and
a plurality of binary optical switches disposed on a planar surface, the plurality of binary optical switch being disposed along the length of the waveguide, each binary optical switch of the plurality of binary optical switches comprising:
a translatable optical grating configured to translate between at least two positions, a first position of the at least two positions being sufficiently close to the waveguide to optically couple between the waveguide and free space beyond the planar surface with a coupling efficiency of at least about 25%, and a second position of the at least two positions being sufficiently far from the waveguide to optically couple between the waveguide and the free space with a coupling efficiency of at most about 5%; and
a MEMS structure configured to selectively translate the translatable optical grating to the first position and to the second position.