Abstract: Structures for an optical switch and methods of forming such structures. The structure comprises a first waveguide core including a first portion and a second portion, a second waveguide core including a first portion and a second portion, a ring resonator having a first portion adjacent to the first portion of the first waveguide core and a second portion adjacent to the first portion of the second waveguide core, and an optical coupler coupled to the second portion of first waveguide core and the second portion of the second waveguide core. The first portion of the ring resonator is spaced from the first portion of the first waveguide core by a first gap over a first light coupling region, and the second portion of the ring resonator is spaced from the first portion of the second waveguide core by a second gap over a second light coupling region.

Abstract: Structures for a phase shifter and methods of forming such structures. The structure comprises a phase shifter including a first section, a second section, and a strip laterally between the first section and the second section. The structure further comprises a waveguide core including a portion laterally between the first section and the second section of the phase shifter, and a dielectric layer between the waveguide core and the phase shifter. The strip is laterally offset relative to the portion of the waveguide core toward the first section of the phase shifter.

Abstract: Photonic structures including ring resonators and methods of forming such structures. The photonic structure comprises first, second, and third waveguide cores, and a first ring resonator arranged between a first portion of the first waveguide core and a portion of the second waveguide core. The photonic structure further comprises a second ring resonator arranged between a second portion of the first waveguide core and a portion of the third waveguide core.

Abstract: Structures for a phase shifter and methods of forming such structures. The structure comprises a first waveguide core, a second waveguide core laterally adjacent to the first waveguide core, and a third waveguide core laterally adjacent to the second waveguide core. The second waveguide core and the first waveguide core are separated by a first slot, and the third waveguide core and the second waveguide core are separated by a second slot. The structure further comprises a layer that overlaps with respective portions of the first waveguide core, the second waveguide core, and the third waveguide core. The layer comprises a first electro-optic material.

Abstract: Structures for a micro-ring resonator filter and methods of forming a structure for a micro-ring resonator filter. The structure comprises a bus-ring coupling section including a first Mach-Zehnder interferometer, and a micro-ring resonator section including a ring resonator coupled to the first Mach-Zehnder interferometer. The ring resonator includes a second Mach-Zehnder interferometer.

Abstract: Structures for a waveguide escalator, as well as methods of forming such structures. The structure comprises a first waveguide core on a substrate, a second waveguide core, and a back-end-of-line stack including a third waveguide core disposed between the first waveguide core and the second waveguide core. The third waveguide core comprises a layer stack that includes a first layer, a second layer, and a third layer between the first layer and the second layer. The first layer and the second layer comprise a first dielectric material with a first refractive index, and the third layer comprises a second dielectric material with a second refractive index that is less than the first refractive index.

Abstract: Disclosed are embodiments of a structure for polarization-independent coarse wavelength division demultiplexing. The structure includes a polarization splitter-rotator (PSR), which receives a dual polarization mode multi-wavelength optical signal and outputs a single polarization mode multi-wavelength optical signal. The structure includes a wavelength division demultiplexer (WDD) and a thermo-optic phase-shifter (TOPS), which is coupled to the PSR and either coupled to the input section of the WDD or integrated into the input section of the WDD. The structure includes at least one photodetector and a thermal control system (TCS). The photodetector is coupled to an unused end of a waveguide in either the TOPS or WDD (depending on the embodiment).

Abstract: Structures for a thermo-optic phase shifter and methods of forming such structures. The structure comprises a waveguide core, and a heater that includes a heating element, a first extension that projects from the first heating element, and a second extension that projects from the heating element. The heating element overlaps with a portion of the waveguide core, and the portion of the waveguide core is positioned laterally between the first extension and the second extension.

Abstract: Structures for a wavelength-division-multiplexing filter and methods of forming a structure for a wavelength-division-multiplexing filter. The structure comprises a first waveguide core including a first phase delay arm and a second waveguide core including a second phase delay arm. The first phase delay arm has a first section and a second section connected to the first section. The first section of the first phase delay arm and the second section of the first phase delay arm are asymmetrical.

Abstract: Structures for a phase shifter and methods of forming such structures. The structure comprises a phase shifter including a first section, a second section, and a strip laterally between the first section and the second section. The structure further comprises a waveguide core including a portion laterally between the first section and the second section of the phase shifter, and a dielectric layer between the waveguide core and the phase shifter. The strip is laterally offset relative to the portion of the waveguide core toward the first section of the phase shifter.

Abstract: Structures for a photonic chip that include an optical signal blocker and methods of forming such structures. The structure comprises a semiconductor substrate, an optical signal blocker including a metal sheet and a plurality of openings in the first metal sheet, and a waveguide core between the semiconductor substrate and the optical signal blocker. The waveguide core includes a portion that is overlapped by the optical signal blocker.

Abstract: Structures for a waveguide escalator, as well as methods of forming such structures. The structure comprises a first waveguide core on a substrate, a second waveguide core, and a back-end-of-line stack including a third waveguide core disposed between the first waveguide core and the second waveguide core. The third waveguide core comprises a layer stack that includes a first layer, a second layer, and a third layer between the first layer and the second layer. The first layer and the second layer comprise a first dielectric material with a first refractive index, and the third layer comprises a second dielectric material with a second refractive index that is less than the first refractive index.

Abstract: Structures for an optical switch and methods of forming such structures. The structure comprises a first waveguide core including a first portion and a second portion, a second waveguide core including a first portion and a second portion, a ring resonator having a first portion adjacent to the first portion of the first waveguide core and a second portion adjacent to the first portion of the second waveguide core, and an optical coupler coupled to the second portion of first waveguide core and the second portion of the second waveguide core. The first portion of the ring resonator is spaced from the first portion of the first waveguide core by a first gap over a first light coupling region, and the second portion of the ring resonator is spaced from the first portion of the second waveguide core by a second gap over a second light coupling region.