Radiation scribed waveguide coupling for photonic circuits

摘要

Optical waveguide coupling ratios can be modified for a package by providing a substrate with a photonic circuit disposed on a first section of the substrate and a plurality of optical waveguides formed in glass disposed on a second section of the substrate, the waveguides being connected to the photonic circuit, adjacent ones of the waveguides having a fixed coupling ratio. A three-dimensional region of the glass abutting an end of one or more of the waveguides is lased to change a refractive index of the glass in each three-dimensional region, and thereby extend a length of each waveguide abutting one of the three-dimensional regions so that the coupling ratio between that waveguide and an adjacent waveguide is changed as a function of the extended length. The lasing is controlled based on feedback so that each coupling ratio changed by the lasing varies by less than a target amount.

主权项

1. A package, comprising:
a substrate; a photonic circuit disposed on a first section of the substrate; a plurality of optical waveguides formed in glass disposed on a second section of the substrate, at least one of the waveguides being connected to the photonic circuit, adjacent ones of the waveguides having a coupling ratio; one or more layers which can block laser light disposed on the first section of the substrate but not on the glass in the second section so that a window is provided through the one or more layers to the glass for laser light; wherein the coupling ratio for at least some of the adjacent waveguides varies by +/−0.1% or less; and wherein at least some of the adjacent waveguides have different coupling ratios so that some of the waveguides are operable to carry light at a lower intensity and other ones of the waveguides are operable to carry light at a higher intensity.