Structures for a polarization switch and methods of fabricating a structure for a polarization switch. A waveguide core is located on a substrate. The waveguide core is composed of silicon nitride. An active layer is positioned proximate to a section of the waveguide core. The active layer composed of a phase change material having a first state with a first refractive index and a second state with a second refractive index.

This patent document provides optical processing and switching of optical channels based on mode-division multiplexing (MDM) and wavelength division multiplexing (WDM). In one implementation, a method is provided for processing different optical signal channels to include receiving different input optical signal channels in different optical waveguide modes and in different wavelengths; converting input optical signal channels in multimodes into single-mode optical signal channels, respectively; subsequent to the conversion, processing single-mode optical signal channels obtained from the different input optical signal channels to re-group single-mode optical signal channels into different groups of processed single-mode optical signal channels; and converting different groups of the processed single-mode optical signal channels into different groups of output optical signal channels containing one or more optical signal channels in multimodes multimode signals to direct the groups as different optical outputs.

Structures for a polarization switch and methods of fabricating a structure for a polarization switch. A waveguide core is located on a substrate. The waveguide core is composed of silicon nitride. An active layer is positioned proximate to a section of the waveguide core. The active layer composed of a phase change material having a first state with a first refractive index and a second state with a second refractive index.

This patent document provides optical processing and switching of optical channels based on mode-division multiplexing (MDM) and wavelength division multiplexing (WDM). In one implementation, a method is provided for processing different optical signal channels to include receiving different input optical signal channels in different optical waveguide modes and in different wavelengths; converting input optical signal channels in multimodes into single-mode optical signal channels, respectively; subsequent to the conversion, processing single-mode optical signal channels obtained from the different input optical signal channels to re-group single-mode optical signal channels into different groups of processed single-mode optical signal channels; and converting different groups of the processed single-mode optical signal channels into different groups of output optical signal channels containing one or more optical signal channels in multimodes multimode signals to direct the groups as different optical outputs.

This patent document provides optical processing and switching of optical channels based on mode-division multiplexing (MDM) and wavelength division multiplexing (WDM). In one implementation, a method is provided for processing different optical signal channels to include receiving different input optical signal channels in different optical waveguide modes and in different wavelengths; converting input optical signal channels in multimodes into single-mode optical signal channels, respectively; subsequent to the conversion, processing single-mode optical signal channels obtained from the different input optical signal channels to re-group single-mode optical signal channels into different groups of processed single-mode optical signal channels; and converting different groups of the processed single-mode optical signal channels into different groups of output optical signal channels containing one or more optical signal channels in multimodes multimode signals to direct the groups as different optical outputs.

A photonic assembly comprising: a first section, the first section comprising a first substrate; and a second section, the second section comprising a second substrate; wherein the photonic assembly comprises an interferometer, the interferometer comprising a plurality of passive photonic elements and a phase modulator; wherein the phase modulator is provided on the second section; and wherein the plurality of passive photonic elements are provided on the first section.

This patent document provides optical processing and switching of optical channels based on mode-division multiplexing (MDM) and wavelength division multiplexing (WDM). In one implementation, a method is provided for processing different optical signal channels to include receiving different input optical signal channels in different optical waveguide modes and in different wavelengths; converting input optical signal channels in multimodes into single-mode optical signal channels, respectively; subsequent to the conversion, processing single-mode optical signal channels obtained from the different input optical signal channels to re-group single-mode optical signal channels into different groups of processed single-mode optical signal channels; and converting different groups of the processed single-mode optical signal channels into different groups of output optical signal channels containing one or more optical signal channels in multimodes multimode signals to direct the groups as different optical outputs.

A polarization beam splitter includes an input port, first and second output ports, and a polarization splitting region coupled between the input port and the first and second output ports. The input port is adapted to receive guided optical signals that are polarization multiplexed, including a transverse electric (TE) optical signal and a transverse magnetic (TM) optical signal. The polarization splitting region includes a pattern of at least two materials having different refractive indexes. The pattern is shaped to demultiplex the TE and TM optical signals by directing a first power majority of the TE optical signal received at the input port to the second output port via asymmetrical power splitting while directing a second power majority of the TM optical signal received at the input port to the first output port via multipath interferometry.

A polarization beam splitter includes an input port, first and second output ports, and a polarization splitting region coupled between the input port and the first and second output ports. The input port is adapted to receive guided optical signals that are polarization multiplexed, including a transverse electric (TE) optical signal and a transverse magnetic (TM) optical signal. The polarization splitting region includes a pattern of at least two materials having different refractive indexes. The pattern is shaped to demultiplex the TE and TM optical signals by directing a first power majority of the TE optical signal received at the input port to the second output port via asymmetrical power splitting while directing a second power majority of the TM optical signal received at the input port to the first output port via multipath interferometry.

An electro-optic device is described. The electro-optic device includes an electro-optic component implemented on an electro-optic material having a slab and a ridge portion. The electro-optic component includes a first portion of the slab and a portion of the ridge portion. The first portion of the slab has a first height. The ridge portion has a second height greater than the first height. A passive functionality component is implemented on a second portion of the slab and is optically coupled with the electro-optic component.