A microheater comprises an optical fiber including a rare earth-doped glass core surrounded by a glass cladding. The rare earth-doped glass core comprises a rare earth dopant at a concentration sufficient for luminescence quenching such that, when the rare earth dopant is pumped with light at an absorption band wavelength, at least about 90% of absorbed pump light is converted into heat.

A rare earth-doped double-clad optical fiber includes a rare earth ion-doped fiber core, an inner cladding layer, and an outer cladding layer. A cross section of the inner cladding layer is a non-circular plane including at least two arcuate notches. According to the provided optical fiber, optical processing can be performed on a preform without changing a preform preparation process and a drawing process. The inner cladding is designed to have a non-circular planar structure having a cross section with at least two arcuate notches. While maintaining the same light absorption efficiency of pump light within the cladding layer, a preform polishing process is simplified, a risk of cracking the preform during polishing of multiple surfaces and a risk of contamination of the preform caused by impurities are reduced, wire drawing control precision is better, and comprehensive performance of the optical fiber is improved.

An optical waveguide includes a cladding layer, a Si layer, a REO layer, and a cap layer. The REO layer is made of a single-crystal rare earth oxide, and is formed on the Si layer. The cap layer is formed on the REO layer. The cap layer may be made of a material transparent to light to be guided. The cap layer has a stripe shape extending in a direction in which light is guided.

Embodiments herein relate to photonic integrated circuits with an on-chip optical isolator. A photonic transmitter chip may include a laser and an on-chip isolator optically coupled with the laser that includes an optical waveguide having a section coupled with a magneto-optic liquid phase epitaxy grown garnet film. In some embodiments, a cladding may be coupled with the garnet film, the on-chip isolator may be arranged in a Mach-Zehnder interferometer configuration, the waveguide may include one or more polarization rotators, and/or the garnet film may be formed of a material from a rare-earth garnet family. Other embodiments may be described and/or claimed.

Systems and methods describe growing RE-based integrated photonic and electronic layered structures on a single substrate. The layered structure comprises a substrate, an epi-twist rare earth oxide layer over a first region of the substrate, and a rare earth pnictide layer over a second region of the substrate, wherein the first region and the second region are non-overlapping.

An optical waveguide includes a cladding layer, a Si layer, a REO layer, and a cap layer. The REO layer is made of a single-crystal rare earth oxide, and is formed on the Si layer. The cap layer is formed on the REO layer. The cap layer may be made of a material transparent to light to be guided. The cap layer has a stripe shape extending in a direction in which light is guided.

A switch module includes a switch integrated circuit (IC), an InP chip, and a planar lightwave circuit (PLC). The InP chip may include a plurality of light sources, an optical splitter, and a plurality of modulators.

Methods for forming magneto-optical films for integrated photonic devices and integrated photonic devices incorporating same are described. An optical isolator or any nonreciprocal photonic component for an integrated photonic device can be fabricated by depositing a functional garnet layer directly onto a non-garnet substrate; depositing a seed garnet layer on the functional garnet layer; and after depositing both the functional garnet layer and the seed layer performing an annealing process. Since the seed garnet layer crystalizes faster than the functional garnet layer, crystallization of the functional garnet layer can be accomplished directly on the non-garnet substrate during a single annealing step for the seed layer and the functional garnet layer.

Methods for forming magneto-optical films for integrated photonic devices and integrated photonic devices incorporating same are described. An optical isolator or any nonreciprocal photonic component for an integrated photonic device can be fabricated by depositing a functional garnet layer directly onto a non-garnet substrate; depositing a seed garnet layer on the functional garnet layer; and after depositing both the functional garnet layer and the seed layer performing an annealing process. Since the seed garnet layer crystalizes faster than the functional garnet layer, crystallization of the functional garnet layer can be accomplished directly on the non-garnet substrate during a single annealing step for the seed layer and the functional garnet layer.

A photonic device includes a substrate and a waveguide supported by the substrate. The waveguide includes a III-nitride-based layer. The III-nitride-based layer is ferroelectric.