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.

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.

A groove having any length is manufactured in a quartz-based waveguide chip without limitation of a chip size. A marker indicating a planned cutting line extending from a connection end surface of a quartz-based waveguide chip in an in-chip plane direction is formed in advance by processing a core layer of the waveguide of the quartz-based waveguide chip, an irradiation position of laser light is aligned with a position of a starting point of the marker in a state where quartz-based waveguide chip is placed on a stage, and a groove is manufactured in the connection end surface of the quartz-based waveguide chip by moving the stage in the extending direction of the marker while irradiating the quartz-based waveguide chip with the laser light from an upper side.

An aluminosilicate glass having a composition according to the following formula (I):

(100−(1+a.sub.1+b.sub.1).Math.x)SiO.sub.2.Math.(x)Al.sub.2O.sub.3.Math.(a.sub.1.Math.x)MO.Math.(b.sub.1.Math.x)R (wt %)  (I)

in which MO is alkaline earth metal oxide, the alkaline earth metal M being one or more of Mg, Ca, Sr, and Ba, R comprises alkali metal oxide, the alkali metal being one or more of Li, Na, and K, x is at least 15, a.sub.1 is at least 0.35, b.sub.1 is at least 0.55, and wherein the product of a.sub.1 and b.sub.1 is at least 0.22.

A groove having any length is manufactured in a quartz-based waveguide chip without limitation of a chip size. A marker indicating a planned cutting line extending from a connection end surface of a quartz-based waveguide chip in an in-chip plane direction is formed in advance by processing a core layer of the waveguide of the quartz-based waveguide chip, an irradiation position of laser light is aligned with a position of a starting point of the marker in a state where quartz-based waveguide chip is placed on a stage, and a groove is manufactured in the connection end surface of the quartz-based waveguide chip by moving the stage in the extending direction of the marker while irradiating the quartz-based waveguide chip with the laser light from an upper side.

Methods and techniques are presented to inhibit crystallization in optical waveguide structures, during high temperature annealing or deposition, thus preventing the formation of crystalline grains that scatter and/or absorb light. Dopant atoms or molecules are used to disrupt crystallization. The dopant atoms or molecules are selected to be transparent to the optical signal's wavelength range(s). Optical signals propagating in a waveguide that is fabricated with such techniques will experience reduced propagation loss or insertion loss. The passive dopants can also be used in active devices such as lasers or optical amplifiers that incorporate optically active dopants, as long as the passive dopants are chosen so that they do not interact with the active dopants.

This disclosure generally relates to systems and methods for improving adhesive bonding between a layer of a device that transmits optical signals, such as a photonics integrated circuit, and a waveguide that helps to transmit at least some of the optical signals. Adhesion methods may include using vapor-phase encapsulation, capillary underfill, or compressive displacement to secure the waveguide to at least one layer of the device that transmits optical signals. In each of these methods, the adhesion method may create an adhesive interface between at least a portion of the waveguide and a contacting layer of the device that transmits optical signals.

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.

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.

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.