Apparatus and methods relating to coupling radiation from an incident beam into a plurality of waveguides with a grating coupler are described. A grating coupler can have offset receiving regions and grating portions with offset periodicity to improve sensitivity of the grating coupler to misalignment of the incident beam.

Apparatus and methods relating to coupling radiation from an incident beam into a plurality of waveguides with a grating coupler are described. A grating coupler can have offset receiving regions and grating portions with offset periodicity to improve sensitivity of the grating coupler to misalignment of the incident beam.

In an example embodiment, a system includes a first grating-coupled laser (GCL) that includes a first laser cavity optically coupled to a first transmit grating coupler configured to redirect horizontally-propagating first light, received from the first laser cavity, vertically downward and out of the first GCL. The system also includes a second GCL that includes a second laser cavity optically coupled to a second transmit grating coupler configured to transmit second light vertically downward and out of the second GCL. The system also includes a photonic integrated circuit (PIC) that includes a first receive grating coupler optically coupled to a first waveguide and configured to receive the first light and couple the first light into the first waveguide. The PIC also includes a second receive grating coupler optically coupled to a second waveguide and configured to receive the second light and couple the second light into the second waveguide.

In an example embodiment, a system includes a first grating-coupled laser (GCL) that includes a first laser cavity optically coupled to a first transmit grating coupler configured to redirect horizontally-propagating first light, received from the first laser cavity, vertically downward and out of the first GCL. The system also includes a second GCL that includes a second laser cavity optically coupled to a second transmit grating coupler configured to transmit second light vertically downward and out of the second GCL. The system also includes a photonic integrated circuit (PIC) that includes a first receive grating coupler optically coupled to a first waveguide and configured to receive the first light and couple the first light into the first waveguide. The PIC also includes a second receive grating coupler optically coupled to a second waveguide and configured to receive the second light and couple the second light into the second waveguide.

Aspects of the disclosure relate to apparatus for the fabrication of waveguides. In one example, an angled ion source is utilized to project ions toward a substrate to form a waveguide which includes angled gratings. In another example, an angled electron beam source is utilized to project electrons toward a substrate to form a waveguide which includes angled gratings. Further aspects of the disclosure provide for methods of forming angled gratings on waveguides utilizing an angled ion beam source and an angled electron beam source.

Aspects of the disclosure relate to apparatus for the fabrication of waveguides. In one example, an angled ion source is utilized to project ions toward a substrate to form a waveguide which includes angled gratings. In another example, an angled electron beam source is utilized to project electrons toward a substrate to form a waveguide which includes angled gratings. Further aspects of the disclosure provide for methods of forming angled gratings on waveguides utilizing an angled ion beam source and an angled electron beam source.

The present invention aims to provide an optical side input/output circuit that has wavelength selectivity and is easily disposed at multiple points in a transmission path, and an optical connector.

The optical side input/output circuit 301 includes: a tap portion 10 in which a tap waveguide 53 that outputs light of a higher-order mode from a side surface of an optical fiber 50 is formed, the light of the higher-order mode being of light propagating in the core 51 of the optical fiber 50; and a grating portion 20 that is located in a stage before the tap portion 10 in the propagation direction of the light, and has a grating 21 that converts light of a desired wavelength from a basic mode to the higher-order mode, the grating 21 being formed in the core 51 of the optical fiber 50.

Techniques relating to an improved optical waveguide are described. The optical waveguide includes an upper and lower waveguide that each comprise a first and second layer, in which photons are transferred from the lower waveguide to the upper waveguide. A structured subwavelength coupling region is included, for example, in the first upper waveguide layer. The fill factor of the subwavelength grating coupling region is increased in the direction of light propagation to increase the index of refraction of the structured subwavelength coupling region and therefore improve photon transfer from the lower waveguide. Additionally, the width of the optical waveguide (at least along the structured subwavelength coupling region) remains constant as the fill factor increases.

Techniques relating to an improved optical waveguide are described. The optical waveguide includes an upper and lower waveguide that each comprise a first and second layer, in which photons are transferred from the lower waveguide to the upper waveguide. A structured subwavelength coupling region is included, for example, in the first upper waveguide layer. The fill factor of the subwavelength grating coupling region is increased in the direction of light propagation to increase the index of refraction of the structured subwavelength coupling region and therefore improve photon transfer from the lower waveguide. Additionally, the width of the optical waveguide (at least along the structured subwavelength coupling region) remains constant as the fill factor increases.

A diffractive optical element and a terminal device are disclosed. The diffractive optical element includes grating components periodically distributed in a first dimension. The grating component includes N optical waveguides. The N optical waveguides include M optical waveguides that periodically change in a second dimension. At least two of the M optical waveguides that periodically change in the second dimension have different structures. An included angle between the second dimension and the first dimension is greater than 0 degrees and less than 180 degrees. N is an integer greater than 1. M is an integer greater than 1 and not greater than N.