Integrated-optics systems are presented in which an active-material stack is disposed on a coupling layer in a first region to collectively define an OA waveguide that supports an optical mode of a light signal. The coupling layer is patterned to define a coupling waveguide and a passive waveguide, which are formed as two abutting, optically coupled segments of the coupling layer. The lateral dimensions of the active-material stack are configured to control the shape and vertical position of the optical mode at any location along the length of the OA waveguide. The active-material stack includes a taper that narrows along its length such that the optical mode is located completely in the coupling waveguide where the coupling waveguide abuts the passive waveguide. In some embodiments, the passive layer is optically coupled with the OA waveguide and a silicon waveguide, thereby enabling light to propagate between them.

Integrated-optics systems are presented in which an active-material stack is disposed on a coupling layer in a first region to collectively define an OA waveguide that supports an optical mode of a light signal. The coupling layer is patterned to define a coupling waveguide and a passive waveguide, which are formed as two abutting, optically coupled segments of the coupling layer. The lateral dimensions of the active-material stack are configured to control the shape and vertical position of the optical mode at any location along the length of the OA waveguide. The active-material stack includes a taper that narrows along its length such that the optical mode is located completely in the coupling waveguide where the coupling waveguide abuts the passive waveguide. In some embodiments, the passive layer is optically coupled with the OA waveguide and a silicon waveguide, thereby enabling light to propagate between them.

A system for optically aligning a photonics die to a fiber array, the fiber array comprising a first and a second fiber channels, the system comprising: the photonics die having: a first and a second optical channels; a first and a second wavelength division multiplexing (WDM) couplers each comprising a bar port, a cross port, and a common port, the first and the second WDM couplers being optically connected to the first and the second optical channels, respectively, via the bar ports and the common ports; and a waveguide crossing optically connecting the cross ports of the first and the second WDM couplers; the system being adapted to couple an optical signal received from the first fiber channel into the cross port of the first WDM coupler and into the waveguide crossing, the optical signal being propagated from the waveguide crossing into the cross port of the second WDM coupler.

An antenna device for performing off-chip light coupling comprising an array of radiating elements whose thickness is larger than λ/2, the radiating elements being chosen such that the length of the array is smaller than 10λ, where λ is the wavelength of light in the material chosen for the radiating elements. An advantage of this method is that, unlike in conventional waveguide grating antenna, by reducing the number of the radiating elements in the array, the dependence of the off-chip emission angle on the wavelength of light can be greatly reduced. Another advantage is that by using thick radiating elements the antenna efficiency can be greatly enhanced, thereby compensating for the reduced efficiency occurring as a consequence of using only a small number of radiating elements in the array.

An antenna device for performing off-chip light coupling comprising an array of radiating elements whose thickness is larger than λ/2, the radiating elements being chosen such that the length of the array is smaller than 10λ, where λ is the wavelength of light in the material chosen for the radiating elements. An advantage of this method is that, unlike in conventional waveguide grating antenna, by reducing the number of the radiating elements in the array, the dependence of the off-chip emission angle on the wavelength of light can be greatly reduced. Another advantage is that by using thick radiating elements the antenna efficiency can be greatly enhanced, thereby compensating for the reduced efficiency occurring as a consequence of using only a small number of radiating elements in the array.

An optical waveguide propagates an optical mode at a first wavelength along a length of the waveguide. The optical waveguide has an optical core with a substantially polygonal cross-section in a plane substantially perpendicular to the length of the waveguide. The optical core has an index of refraction n1 at the first wavelength. A first optical cladding is disposed adjacent the optical core and has an index of refraction n2 at the first wavelength, n2<n1. A spatially modulated index region has alternating higher and lower index regions extending along a width, and arranged along the length, of the optical waveguide, and configured to extract an optical mode that would otherwise propagate along the length of the waveguide.

An optical waveguide propagates an optical mode at a first wavelength along a length of the waveguide. The optical waveguide has an optical core with a substantially polygonal cross-section in a plane substantially perpendicular to the length of the waveguide. The optical core has an index of refraction n1 at the first wavelength. A first optical cladding is disposed adjacent the optical core and has an index of refraction n2 at the first wavelength, n2<n1. A spatially modulated index region has alternating higher and lower index regions extending along a width, and arranged along the length, of the optical waveguide, and configured to extract an optical mode that would otherwise propagate along the length of the waveguide.

A photonic integrated circuit chip includes a substrate and a wafer on the substrate. The wafer itself includes a photonic grating coupler with a taper portion and grating features. The grating features extend from the taper portion toward the substrate.

A photonic integrated circuit chip includes a substrate and a wafer on the substrate. The wafer itself includes a photonic grating coupler with a taper portion and grating features. The grating features extend from the taper portion toward the substrate.

An output coupler can be used to couple multiple channels of light from a semiconductor waveguide to an optical fiber for wavelength division multiplexing. To couple light of a wide bandwidth (e.g., equal to or greater than 100 nm), two symmetrical gratings on two sides of a Fabry Perot cavity is used. The two symmetrical gratings are optimized to both reflect light for a Fabry Perot resonator and couple light out of the semiconductor waveguide.