A thermo-optic phase shifter comprises an optical waveguide comprising a P-type region comprising a first contact, an N-type region comprising a second contact, and a waveguide region disposed between the P-type region and the N-type region and having a raised portion. The thermo-optic phase shifter further comprises one or more heating elements. The one or more heating elements include one or more discrete resistive heating elements or the P-type and N-type regions driven as resistive heating elements.

An optical sensing module suitable for wearable devices, the optical sensing module comprising: a silicon or silicon nitride transmitter photonic integrated circuit (PIC), the transmitter PIC comprising: a plurality of lasers, each laser of the plurality of lasers operating at a wavelength that is different from the wavelength of the others; an optical manipulation region, the optical manipulation region comprising one or more of: an optical modulator, optical multiplexer (MUX); and additional optical manipulation elements; and one or more optical outputs for light originating from the plurality of lasers.

An optical phase shifter may include a waveguide core that has a top surface, and a semiconductor contact that is laterally displaced relative to the waveguide core and is electrically connected to the waveguide core. A top surface of the semiconductor contact is above the top surface of the waveguide core. The waveguide core may include a p-type core region and an n-type core region. A p-type semiconductor region may be in physical contact with the n-type core region of the waveguide core, and an n-type semiconductor region may be in physical contact with the p-type core region of the waveguide core. A phase shifter region and a light-emitting region may be disposed at different depth levels, and the light-emitting region may emit light from a phase shifter region that is in a position adjacent to the light-emitting region.

An optical phase shifter may include a waveguide core that has a top surface, and a semiconductor contact that is laterally displaced relative to the waveguide core and is electrically connected to the waveguide core. A top surface of the semiconductor contact is above the top surface of the waveguide core. The waveguide core may include a p-type core region and an n-type core region. A p-type semiconductor region may be in physical contact with the n-type core region of the waveguide core, and an n-type semiconductor region may be in physical contact with the p-type core region of the waveguide core. A phase shifter region and a light-emitting region may be disposed at different depth levels, and the light-emitting region may emit light from a phase shifter region that is in a position adjacent to the light-emitting region.

An optical circuit of the present disclosure shares at least a part of an electrical path including phase variable means between neighboring optical interference circuits, or configures an electrical path so as to straddle neighboring optical interference circuits, thereby performing electrical or thermal feedback. The optical circuit includes a mechanism using the electrical or thermal feedback for cancelling components of thermal crosstalk from one optical interference circuit to another neighboring optical interference circuit. The optical circuit of the present disclosure has a resistor element that shares electrical paths including respective phase variable means between the neighboring optical interference circuits. The optical circuit changes the phase change amount by the phase variable means in the neighboring optical interference circuit, in such a way as to cancel the thermal crosstalk components by the resistor element.

An optical circuit of the present disclosure shares at least a part of an electrical path including phase variable means between neighboring optical interference circuits, or configures an electrical path so as to straddle neighboring optical interference circuits, thereby performing electrical or thermal feedback. The optical circuit includes a mechanism using the electrical or thermal feedback for cancelling components of thermal crosstalk from one optical interference circuit to another neighboring optical interference circuit. The optical circuit of the present disclosure has a resistor element that shares electrical paths including respective phase variable means between the neighboring optical interference circuits. The optical circuit changes the phase change amount by the phase variable means in the neighboring optical interference circuit, in such a way as to cancel the thermal crosstalk components by the resistor element.

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.

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.

The invention refers to a frequency shifter for heterodyne interferometry measurements, comprising a chip, an input waveguide configured to guide a light beam, at least four phase modulators, each being arranged to receive the light beam from the input waveguide and configured to modulate a phase of the light beam, an output combiner being arranged to let the light beams modulated by each phase modulator interfere, a first output waveguide coupled to the output combiner and configured to receive the modulated light beams constructively interfering at the output combiner, a second output waveguide coupled to the output combiner and configured to receive the modulated light beams destructively interfering at the output combiner, wherein the input waveguide, the phase modulators, the output combiner, the first output waveguide and the second output waveguide are arranged on the chip.

A silicon optical modulator is fabricated to have a multi-slab structure between the contacts and the waveguide, imparting desirable performance attributes. A first slab comprises dopant of a first level. A second slab adjacent to (e.g., on top of) the first slab, comprises a doped region proximate to a contact, and an intrinsic region proximate to the waveguide. The parallel resistance properties and low overlap between the highly doped silicon and optical mode pigtail afforded by the multi-slab configuration, allow the modulator to operate with reduced optical losses and at a high speed. Embodiments may be implemented in a Mach-Zehnder interferometer or in micro-ring resonator modulator configuration.