A photonic aerosol particle sensor includes a plurality of photonic waveguide resonators each having a photonic waveguide disposed along a separate waveguide resonator path and each photonic waveguide having a lateral waveguide width different than the waveguide width of other photonic waveguide resonators in the plurality. All waveguides in the plurality of photonic waveguide resonators have a common vertical thickness and are formed of a common photonic waveguide material. An optical input connection couples light into the waveguide resonators. A particle input conveys aerosol particles toward the waveguide resonators and an aerosol particle output conveys aerosol particles away from the waveguide resonators. At least one optical output connection is optically connected to accept light out of the plurality of photonic waveguide resonators to provide a signal indicative of at least one characteristic of the aerosol particles to be analyzed.

A ring resonator electro-optical device includes a first silicon nitride waveguide and a second annular silicon waveguide that comprises a first section running under a second section of the first waveguide. The second waveguide also includes an annular silicon strip having a cross-section increasing in the first section from a minimum cross-section located under the second section.

Provided is a light detection and ranging (LiDAR) apparatus including a light source configured to generate light, an optical transmitter configured to emit the light generated by the light source to outside of the LiDAR apparatus, an optical receiver configured to receive light from the outside of the LiDAR apparatus, a resonance-type photodetector configured to selectively amplify and detect light having a same wavelength as a wavelength of light generated by the light source among the light received by the optical receiver, and a processor configured to control the light source and the resonance-type photodetector, wherein the resonance-type photodetector includes a resonator, a phase modulator provided on the resonator and configured to control a phase of light traveling along the resonator based on control of the processor, and an optical detector configured to detect an intensity of the light traveling along the resonator.

Methods and apparatus are provided for switching an optical signal. In one aspect, an optical switching apparatus comprises a first beam splitting apparatus configured to split a first optical input signal into first and second optical signals, wherein the first optical signal has substantially the same polarization state as the second optical signal. The apparatus also comprises a switching matrix comprising a plurality of first outputs of the switching matrix and a plurality of second outputs of the switching matrix, each first output of the switching matrix associated with a respective one of the second outputs of the switching matrix, the switching matrix configured to selectively direct the first optical signal to a selected one of the first outputs of the switching matrix and to selectively direct the second optical signal to the second output of the switching matrix associated with the selected first output of the switching matrix. The apparatus further comprises a plurality of beam combining apparatus, each beam combining apparatus configured to combine optical signals from a respective one of the first outputs of the switching matrix and its associated second output of the switching matrix.

One or more optical resonators are coupled to an optical waveguide in sequence. Each of the resonators includes a corresponding modulator. A signal controller is configured to electrically drive each modulator with a corresponding composite electrical signal. Each composite electrical signal includes two or more frequency components of a frequency comb defined by the one or more resonators. The result of this configuration is that an input-output relation between an input of the waveguide and an output of the waveguide is a linear transformation defined by the composite electrical signals using frequencies of the frequency comb as a basis. Such linear transformations can be reciprocal or non-reciprocal, unitary or non-unitary.

Various indirect feedback tuning apparatuses and methods for tuning photonic systems are enabled. For instance, a system can perform operations, such as: determining a temperature of an optical device, determining, based on the temperature of the optical device and a feedback model, a tuning input to stabilize an optical signal, and performing, based on the tuning input, feedback tuning, wherein the feedback tuning comprises thermal tuning and electrical tuning.

An integrated photonics optical gyroscope fabricated on a silicon nitride (SiN) waveguide platform comprises a first straight waveguide to receive incoming light and to output outgoing light to be coupled to a photodetector to provide an optical signal for rotational sensing. The gyroscope comprises a first microresonator ring proximate to the first straight waveguide. Light evanescently couples from the first straight waveguide to the first microresonator ring and experiences propagation loss while circulating as a guided beam within the first microresonator ring. The guided beam evanescently couples back from the first microresonator ring to the first straight waveguide to provide the optical signal for rotational sensing after optical gain is imparted to guided beam to counter the propagation loss. In a coupled-ring configurations, the first microresonator ring acts as a loss ring, and optical gain is imparted to a second microresonator ring which acts as a gain ring.

An optical device is provided. The optical device includes a ring waveguide and a bus waveguide. The ring waveguide includes a coupling region. The bus waveguide is disposed adjacent to and spaced apart from the coupling region of the ring waveguide. The bus waveguide includes a coupling structure corresponding to the coupling region.

An athermal optical waveguide structure such as an optical add drop multiplexer (OADM) or the like is fabricated by a method that includes forming a lower cladding layer on a substrate. A waveguiding core layer is formed on the lower cladding layer. An upper cladding layer is formed on the waveguiding core layer and the lower cladding layer a sol-gel material. The sol-gel material includes an organically modified siloxane and a metal oxide. A thermo-optic coefficient of the sol-gel material is adjusted by curing the sol-gel material for a selected duration of time at a selected temperature such that the thermo-optic coefficient of the sol-gel material compensates for a thermo-optic coefficient of at least the waveguiding core layer such that an effective thermo-optic coefficient of the optical waveguide structure at a specified optical wavelength and over a specified temperature range is reduced.

Embodiments disclosed herein include an optoelectronic system. In an embodiment, the optoelectronic system comprises a first substrate, a second substrate over the first substrate, and a micro-ring resonator (MRR) over the second substrate. In an embodiment, a heater is integrated into the MRR, a cladding is over the MRR, and a temperature sensor is over the MRR in the cladding.