An integrated Mach-Zehnder Interferometer comprising: an upper arm and a lower arm; and a differential thermo-optic phase shifter comprising a first heating element and a second heating element collocated with the upper arm and the lower arm, respectively, the first heating element having a first resistance and the second heating element having a second resistance, an upper pad electrically connected to the first heating element, the upper pad being adapted to receive a first voltage, a lower pad electrically connected to the second heating element, the lower pad being adapted to receive a second voltage, and a common pad electrically connected to the first heating element and the second heating element, the common pad being adapted to receive a third voltage; wherein, when the first, the second, and the third voltages are applied to the upper, the lower, and the common pads, respectively, a phase shift difference is thermally produced.

The present disclosure relates to implementations of a photonic circuit, and particularly to a photonic circuit that includes one or more matrix circuits. For example, the present disclosure relates to photonic circuit implementations of unitary matrices, and of arbitrary real and/or complex matrices factorized using unitary matrices, that utilize special generalized Mach-Zehnder interferometers (SGMZIs) as building blocks of various matrix circuit architectures.

A Mach-Zehnder interferometer (MZI) filter comprising one or more passive compensation structures are described. The passive compensation structures yield MZI filters that are intrinsically tolerant to perturbations in waveguide dimensions and/or other ambient conditions. The use of n+1 waveguide widths can mitigate n different sources of perturbation to the filter. The use of at least three different waveguide widths for each Mach-Zehnder waveguide can alleviate sensitivity of filter performance to random width or temperature variations. A tolerance compensation portion is positioned between a first coupler section and a second coupler section, wherein the tolerance compensation portion includes a first compensation section having a second width, a second compensation section having a third width and a third compensation section having a fourth width, wherein the fourth width is greater than the third width and the third width is greater than the second width.

Refractory anchoring devices include a main body and a mounting feature for mounting to a thermal vessel. The main body has the shape of two end-to-end Y's forming a central segment, two branch segments extending from each end of the central segment, and an extension segment extending from each of the four branch segments, to collectively form four unenclosed cell openings that are each semi-hexagonal in shape. Some embodiments include four reinforcement segments with each one extending into a respective cell opening, four voids with each one extending through respective adjacent branch and extension segments, an underbody gap formed under the central segment for refractory interlinking between cell openings, and/or a single stud-welding stud for the mounting feature. Refractory anchoring systems and methods include an array of the refractory anchoring devices arranged and mounted so that the unenclosed semi-hexagonal cell openings of adjacent anchoring devices cooperatively form substantially hexagonal cells.

Refractory anchoring devices include a main body and a mounting feature for mounting to a thermal vessel. The main body has the shape of two end-to-end Y's forming a central segment, two branch segments extending from each end of the central segment, and an extension segment extending from each of the four branch segments, to collectively form four unenclosed cell openings that are each semi-hexagonal in shape. Some embodiments include four reinforcement segments with each one extending into a respective cell opening, four voids with each one extending through respective adjacent branch and extension segments, an underbody gap formed under the central segment for refractory interlinking between cell openings, and/or a single stud-welding stud for the mounting feature. Refractory anchoring systems and methods include an array of the refractory anchoring devices arranged and mounted so that the unenclosed semi-hexagonal cell openings of adjacent anchoring devices cooperatively form substantially hexagonal cells.

An optical coherent transceiver comprising a polarization and phase-diversity coherent receiver and a polarization and phase-diversity modulator on the same substrate interfaced by three grating couplers, one grating coupler coupling in a signal, one grating coupler coupling in a laser signal, and a third grating coupler coupling out a modulated signal.

The method object of the invention enables the scalable configuration and performance optimisation to be carried out for programmable optical circuits based on meshed structures, in such a way that they can perform optical/quantum signal processing functions. The object of the invention can be applied in circuits with arbitrary degrees of complexity implemented by means of programming a waveguide mesh. The method object of the invention enables not only the analysis and evaluation of performance to be carried out, but also the subsequent programming and optimisation of programmable optical devices.

A photonic integrated circuit for an interferometric sensor includes a first waveguide called sensitive arm wherein a first portion of the light radiation is propagated, the sensitive arm being exposed to a first ambient medium and to at least one compound to be detected inducing a modification of the local refractive index perceived by the evanescent part of the electromagnetic field of the first portion of the light radiation, and a second waveguide called reference arm wherein a second portion of the light radiation is propagated, an encapsulation layer encapsulating the reference arm, the encapsulation layer being impermeable to the compound or compounds to be detected, so that the reference arm is exposed only to a second ambient medium, substantially of the same nature as the first ambient medium and without the compound to be detected and interferometric sensor comprising a photonic integrated circuit according to the invention.

A method includes receiving Bell pairs. Photons are obtained in a Greenberger-Hom-Zeilinger (GHZ) state by providing, to a first beam splitter, a photon from a first Bell pair and a photon from a second Bell pair. The first beam splitter is coupled with a first output channel and a second output channel. Obtaining the photons in the GHZ state further includes providing, to a second beam splitter, a photon from a third Bell pair and a photon from a fourth Bell pair. The second beam splitter is coupled with a third output channel arid a fourth output channel. Obtaining the photons in the GHZ state further includes providing a photon output from the second output channel as a first input to a detector and a photon output in the third output channel a second input to the first detector.

The invention relates to a photonic circuit for attenuating the amplitude of an optical signal, comprising a Mach-Zehnder interferometer for coupling an input waveguide (14) and an output waveguide (15), said interferometer comprising a modulation section (SM1) which includes a first waveguide (11), a second waveguide (12) and a phase shifter (13) configured to introduce a phase difference between a first optical signal circulating on the first waveguide and a second optical signal circulating on the second waveguide. The first and second waveguides are arranged in two distinct parallel layers and the phase shifter is a thermo-optical phase shifter arranged to preferentially act on one of the first and second waveguides.