Abstract: A method of fabricating a composite semiconductor structure includes providing a first substrate comprising a first material and having a first surface and forming a plurality of pedestals extending to a predetermined height in a direction normal to the first surface. The method also includes attaching a plurality of elements comprising a second material to each of the plurality of pedestals, providing a second substrate having one or more structures disposed thereon, and aligning the first substrate and the second substrate. The method further includes joining the first substrate and the second substrate to form the composite substrate structure and removing at least a portion of the first substrate from the composite substrate structure.

Abstract: A method of operating a BPSK modulator includes receiving an RF signal at the BPSK modulator and splitting the RF signal into a first portion and a second portion that is inverted with respect to the first portion. The method also includes receiving the first portion at a first arm of the BPSK modulator, receiving the second portion at a second arm of the BPSK modulator, applying a first tone to the first arm of the BPSK modulator, and applying a second tone to the second arm of the BPSK modulator. The method further includes measuring a power associated with an output of the BPSK modulator and adjusting a phase applied to at least one of the first arm of the BPSK modulator or the second arm of the BPSK modulator in response to the measured power.

Abstract: A waveguide coupler includes a first waveguide and a second waveguide. The waveguide coupler also includes a connecting waveguide disposed between the first waveguide and the second waveguide. The connecting waveguide includes a first material having a first index of refraction and a second material having a second index of refraction higher than the first index of refraction.