Embodiments described herein may be related to apparatuses, processes, and techniques directed to dense integration of PICs in a substrate using an optical fanout structure that includes waveguides formed within a substrate to optically couple with the PICs at an edge of the substrate. One or more PICs may then be electrically with dies such as processor dies or memory dies. The one or more PICs may be located within a cavity in the substrate. The substrate may be made of glass or silicon. Other embodiments may be described and/or claimed.

The method for inscribing a waveguide into a media glass substrate generally has the steps of: relatively moving a femtosecond laser beam along a surface of the media glass substrate while maintaining the focus of the laser beam at a depth of less than the surface, wherein the waveguide has a loss of less than 0.2 dB/cm when measured at a wavelength of light signal propagating in the waveguide during normal use of the waveguide. Particularly, the method can have varying writing parameters according to whether the waveguide is single-mode or multi-mode.

A method for fabricating a photonic integrated circuit (PIC), where the method includes providing a first PIC die including a first optical component covered by a first dielectric layer; performing a location specific ion beam planarizing of the first dielectric layer to form a first planarized surface; providing a second PIC die including a second optical component covered by a second dielectric layer; performing a planarizing of the second dielectric layer to form a second planarized surface; and bonding the first planarized surface of the first PIC die to the second planarized surface of the second PIC die to form a three dimensional (3D) stacked PIC die.

The channel waveguides disclosed herein have bend compensation in the form of at least one compensated bend section. The channel waveguides are formed in a glass-based substrate having a glass-based matrix. The channel waveguide has an waveguide IOX region with a straight section and a bend section. The waveguide IOX region at the bend section is superimposed with a quasi-linear modifying IOX region to form a compensated bend IOX region that defines the compensated bend section. The compensated bend section has a reduced amount of optical loss as compared to if the compensated bend section had a refractive index profile that was the same as the straight section. Methods of forming the compensated bend sections for the channel waveguides are also disclosed.

The channel waveguides disclosed herein have bend compensation in the form of at least one compensated bend section. The channel waveguides are formed in a glass-based substrate having a glass-based matrix. The channel waveguide has an waveguide IOX region with a straight section and a bend section. The waveguide IOX region at the bend section is superimposed with a quasi-linear modifying IOX region to form a compensated bend IOX region that defines the compensated bend section. The compensated bend section has a reduced amount of optical loss as compared to if the compensated bend section had a refractive index profile that was the same as the straight section. Methods of forming the compensated bend sections for the channel waveguides are also disclosed.

The glass waveguide assembly includes a substrate with glass optical waveguides formed in the body of the glass substrate without adding or removing any glass from the substrate body. The glass optical waveguides run generally from a front-end section to a back-end section. A protective coating is formed over at least a portion of the top surface of the glass substrate where the glass optical waveguides reside. Optical connectors are formed at or adjacent the back end at corresponding connector regions. Each connector includes an end portion of at least one of the glass optical waveguides. In some configurations, the glass waveguide assembly includes a bend section that facilitates forming an optical interconnection in a photonic system between an optical-electrical printed circuit board and photonic integrated circuit.

Disclosed herein is a fiber optic-to-waveguide coupling assembly with an overlap for edge coupling. The fiber optic-to-waveguide coupling assembly includes a first coupler having a substrate and at least one data fiber, and an interposer with at least one waveguide. A first coupler overlap portion of the substrate is positionable proximate a first interposer overlap portion of the interposer to form a first overlap therebetween to align the at least one data fiber with the at least one waveguide. The substrate and the interposer may each include complementary alignment features to further align the at least one data fiber and the at least one waveguide. The fiber optic-to-waveguide coupling assembly provides simple and accurate alignment with simplified manufacture and assembly.

The glass waveguide assembly includes a substrate with glass optical waveguides formed in the body of the glass substrate without adding or removing any glass from the substrate body. The glass optical waveguides run generally from a front-end section to a back-end section. A protective coating is formed over at least a portion of the top surface of the glass substrate where the glass optical waveguides reside. Optical connectors are formed at or adjacent the back end at corresponding connector regions. Each connector includes an end portion of at least one of the glass optical waveguides. In some configurations, the glass waveguide assembly includes a bend section that facilitates forming an optical interconnection in a photonic system between an optical-electrical printed circuit board and photonic integrated circuit.