A wavelength calibration method for a microring filter includes selecting N wavelengths from M wavelengths, and performing operations on the microring filter for each of the N wavelengths, thereby obtaining N sets of calibrated voltages, and obtaining, based on N sets of calibrated voltages, M−N sets of calibrated voltages corresponding to M−N wavelengths of the M wavelengths. The operating include adjusting thermal tuning power of the plurality of microrings in response to one set of voltages, and obtaining a plurality of sets of voltages that enable monitored optical power to have an extreme value, and using the plurality of sets of voltages as a reference, adjusting the thermal tuning power of the plurality of microrings in response to another set of voltages, and determining one of the N sets of calibrated voltages from the plurality of sets of voltages.

An optical device is provided. The optical device includes a substrate and a plurality of filters. The plurality of filters are disposed over the substrate. Each of the filters includes a support body, a filter layer, and a centrosymmetric spacer. The support body has a first side surface and a second side surface opposite to the first side surface. The filter layer is on the first side surface. The spacer is attached to the first side surface by a second adhesive layer on the first side surface. The centrosymmetric spacer is attached to the filter layer, at least a peripheral portion of the filter layer is free from being covered by the centrosymmetric spacer.

The present invention provides a temperature-insensitive Mach-Zehnder interferometer, including: a first mode converter; a second mode converter, located on one side of the first mode converter and with a distance from the first mode converter; and a connecting arm, located between the first mode converter and the second mode converter, one end of the connecting arm is connected with the first mode converter, and the other end is connected with the second mode converter. The connecting arm includes a straight waveguide connecting arm. The temperature-insensitive Mach-Zehnder interferometer of the present invention can be configured to be insensitive to temperature by adjusting parameters such as the width and thickness of the connecting arm.

An optical module includes: a substrate and a waveguide element having a mount face opposed to the substrate, the waveguide element having an interference waveguide portion having an optical interference function. Further, the mount face includes a projection region to which the interference waveguide portion is projected on the mount face and a non-projection region, and the waveguide element is joined to the substrate with a joint material in the non-projection region.

An optical apparatus, comprising a semiconductor substrate, a dielectric layer located on the semiconductor substrate, wherein a membrane portion of the dielectric layer is located over a cavity in a surface of the semiconductor substrate, a resistive heater located on the membrane portion, the resistive heater being controllable by a current applied to the resistive heater and an etalon optical filter located on the resistive heater and over the cavity, an optical passband of the etalon optical filter being wavelength tunable by the resistive heater. A method of manufacturing the optical apparatus is also disclosed.

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.

Optical telecommunication receivers and transmitters are described comprising dispersive elements and adjustable beam steering elements that are combined to provide optical grid tracking to adjust with very low power consumption to variations in the optical grid due to various changes, such as temperature fluctuations, age or other environmental or design changes. Thus, high bandwidth transmitters or receivers can be provides with low power consumption and/or low cost designs.

Optical system comprising two optical fibres which are configured to define between them a Fabry-Perot cavity, and a connecting element bonded to each of the two optical fibres, the connecting element defining a through-passage, at least one of the two optical fibres comprising an end portion arranged in the through-passage and bonded to the connecting element, the two optical fibres extending along an axis and being separated from one another by a distance Le parallel to the axis, one of the optical fibres being bonded to the connecting element at a first bonding zone, and the other optical fibre being bonded to the connecting element at a second bonding zone separated from the first bonding zone by distance parallel to the axis.

A photonic integrated circuit includes a slot optical waveguide having an optical core with sub-wavelength slot therein that is partially filled with a first lower-index material having a negative thermo-optic coefficient. The slot may also include a second lower-index material having a positive thermo-optic coefficient. The relative volume of the first lower-index material within the slot may be configured to provide athermal or nearly-athermal operation. Example applications include integrated AWG MUX/DEMUX devices, Mach-Zehnder modulators, and micro-ring resonators or modulators implemented with silicon-based or silicon-nitride based slot waveguides with reduced sensitivity to temperature changes.

An optical device that includes means for thermal stabilization and control is described. The optical device can be a ring resonator, or another device that requires accurate control of the phase of the optical signal. In an example involving an optical resonator, a thermal stabilization system includes a temperature sensor, a control circuit, and a heater local to the resonator. The temperature sensor can be a bandgap temperature sensor formed of a pair of matched p/n junctions biased in operation at different junction currents.