Abstract: An article of manufacture comprises a bottom volume comprising a first region composed of a first material characterized by a first index of refraction (IOR) and having a first thickness, and thinned regions in which a portion of the first material is absent or has a thickness less than the first thickness; a middle volume on top of the bottom volume and comprising a second material characterized by a second IOR smaller than the first IOR; and a top volume on top of the middle volume and comprising alignment structures, and a photonic structure; where the top and middle volumes are in contact at an interface plane, and spatial coordinates specify two-dimensional positions, within at least one thinned region in a second plane parallel to the interface plane and with respect to the alignment structures, of portions of the photonic structure in a first plane parallel to the interface plane.

Abstract: An integrated circuit comprises: at least one photonic layer that includes one or more optical waveguides; a first optical coupler that couples at least a first optical mode outside of the photonic layer to a first waveguide in the photonic layer; a photonic device that includes one or more ports in the photonic layer; a first multi-port optical coupler that includes three or more ports in the photonic layer, including a first port optically coupled to the first optical coupler, a second port optically coupled to a first port of the photonic device, and a third port optically coupled to a first optical reflector configured to send substantially all optical power emitted from the third port of the first multi-port optical coupler back to the third port of the first multi-port optical coupler.

Abstract: An optical modulator includes a rib; and a slab interconnected to both sides of the rib; wherein the rib is dimensioned relative to the slab to support guiding of a Transverse Magnetic (TM) mode with a main lobe that propagates orthogonal to the slab and with the main lobe substantially excluded from the slab. The rib guides wavelengths in an infrared range in the TM mode. A height of the rib, relative to the slab, is about half of a width of the rib, between the slab.

Abstract: An integrated circuit comprises: at least one photonic layer that includes one or more optical waveguides; a first optical coupler that couples at least a first optical mode outside of the photonic layer to a first waveguide in the photonic layer; a photonic device that includes one or more ports in the photonic layer; a first multi-port optical coupler that includes three or more ports in the photonic layer, including a first port optically coupled to the first optical coupler, a second port optically coupled to a first port of the photonic device, and a third port optically coupled to a first optical reflector configured to send substantially all optical power emitted from the third port of the first multi-port optical coupler back to the third port of the first multi-port optical coupler.

Abstract: An integrated circuit comprises: at least one photonic layer that includes one or more optical waveguides; a first optical coupler that couples at least a first optical mode outside of the photonic layer to a first waveguide in the photonic layer; a photonic device that includes one or more ports in the photonic layer; a first multi-port optical coupler that includes three or more ports in the photonic layer, including a first port optically coupled to the first optical coupler, a second port optically coupled to a first port of the photonic device, and a third port optically coupled to a first optical reflector configured to send substantially all optical power emitted from the third port of the first multi-port optical coupler back to the third port of the first multi-port optical coupler.

Abstract: An integrated circuit comprises: at least one photonic layer that includes one or more optical waveguides; a first optical coupler that couples at least a first optical mode outside of the photonic layer to a first waveguide in the photonic layer; a photonic device that includes one or more ports in the photonic layer; a first multi-port optical coupler that includes three or more ports in the photonic layer, including a first port optically coupled to the first optical coupler, a second port optically coupled to a first port of the photonic device, and a third port optically coupled to a first optical reflector configured to send substantially all optical power emitted from the third port of the first multi-port optical coupler back to the third port of the first multi-port optical coupler.

Abstract: An optical modulator includes a rib; and a slab interconnected to both sides of the rib; wherein the rib is dimensioned relative to the slab to support guiding of a Transverse Magnetic (TM) mode with a main lobe that propagates orthogonal to the slab and with the main lobe substantially excluded from the slab. The rib guides wavelengths in an infrared range in the TM mode. A height of the rib, relative to the slab, is about half of a width of the rib, between the slab.

Abstract: A silicon photonics modulator includes a rib that is a PN junction; a slab including a P doped region adjacent to the waveguide core on a first side and an N doped region adjacent to the waveguide core on a second side, opposite the first side; and a first electrode connected to the P-doped region and a second electrode connected to the N-doped region, wherein the rib is dimensioned to support guiding of a Transverse Magnetic (TM) mode with a main lobe that propagates orthogonal to the slab. The rib guides wavelengths in an infrared range in the TM mode.

Abstract: A silicon photonics modulator includes a rib that is a PN junction; a slab including a P doped region adjacent to the waveguide core on a first side and an N doped region adjacent to the waveguide core on a second side, opposite the first side; and a first electrode connected to the P-doped region and a second electrode connected to the N-doped region, wherein the rib is dimensioned to support guiding of a Transverse Magnetic (TM) mode with a main lobe that propagates orthogonal to the slab. The rib guides wavelengths in an infrared range in the TM mode.

Abstract: An optical interferometer based on multi-mode interference (MMI) devices includes an input port, an output port, a first MMI device connected to the input port at an input face of the first MMI device, a second MMI device connected to the first output port at an output face of the second MMI device. In the optical interferometer, an output face of the first MMI device and an input face of the second MMI device are directly connected, the first MMI device includes a first and a second self-imaging points at an interface between the first MMI device and the second MMI device, and a propagation axis of the second MMI device is tilted with respect to a propagation axis of the first MMI device, causing a path length difference between an upper optical path via the first self-imaging point and a lower optical path via the second self-imaging point.

Abstract: An optical interferometer based on multi-mode interference (MMI) devices includes an input port, an output port, a first MMI device connected to the input port at an input face of the first MMI device, a second MMI device connected to the first output port at an output face of the second MMI device. In the optical interferometer, an output face of the first MMI device and an input face of the second MMI device are directly connected, the first MMI device includes a first and a second self-imaging points at an interface between the first MMI device and the second MMI device, and a propagation axis of the second MMI device is tilted with respect to a propagation axis of the first MMI device, causing a path length difference between an upper optical path via the first self-imaging point and a lower optical path via the second self-imaging point.

Abstract: A phase modulator with reduced Residual Amplitude Modulation includes a main path; a correction path; a first coupler configured to split, at a first ratio, an input to the main path and the correction path; and a second coupler configured to combine outputs from the main path and the correction path and to split the combined outputs, at a second ratio, with a first output comprising an output of the phase modulator with the reduced Residual Amplitude Modulation. The correction path can include a correction signal with a proper amplitude and phase that, when combined with an output signal from the main path by the second coupler, cancels the Residual Amplitude Modulation from the output signal.

Abstract: A phase modulator with reduced Residual Amplitude Modulation includes a main path; a correction path; a first coupler configured to split, at a first ratio, an input to the main path and the correction path; and a second coupler configured to combine outputs from the main path and the correction path and to split the combined outputs, at a second ratio, with a first output comprising an output of the phase modulator with the reduced Residual Amplitude Modulation. The correction path can include a correction signal with a proper amplitude and phase that, when combined with an output signal from the main path by the second coupler, cancels the Residual Amplitude Modulation from the output signal.

Abstract: An optical interferometer based on multi-mode interference (MMI) devices includes an input port, an output port, a first MMI device connected to the input port at an input face of the first MMI device, a second MMI device connected to the first output port at an output face of the second MMI device. In the optical interferometer, an output face of the first MMI device and an input face of the second MMI device are directly connected, the first MMI device includes a first and a second self-imaging points at an interface between the first MMI device and the second MMI device, and a propagation axis of the second MMI device is tilted with respect to a propagation axis of the first MMI device, causing a path length difference between an upper optical path via the first self-imaging point and a lower optical path via the second self-imaging point.