High-efficiency optical waveguide transitions

摘要

Embodiments describe high-efficiency optical waveguide transitions—i.e., creating heterogeneous transitions between Si and III-V semiconductor regions or devices with minimal reflections. This is advantageous for III-V device performance, e.g. for an on-chip lasers achieving lower relative intensity noise (RIN) and lower phase noise by avoiding reflections, higher gain and reduced gain-ripple from an semiconductor optical amplifier (SOA) by avoiding internal reflections in the SOA. Furthermore, in some embodiments, generated photocurrent can be used as a monitor signal for control purposes, thereby avoiding the use of separate tap-monitor photodetectors, which provide additional link loss.

主权项

1. An apparatus, comprising:
a first waveguide comprising a first material, the first material being a semiconductor or a dielectric; a second waveguide disposed over the first waveguide and configured to transfer light to the first waveguide, the second waveguide comprising a second material different from the first material, the second material being a semiconductor or a dielectric, the second waveguide including:
a first region aligned with at least a portion of the first waveguide; anda second region laterally offset from the first region;wherein at least one of the first waveguide or the second waveguide includes a tapered region configured to adiabatically transfer light between the first and second waveguides, andwherein the second region of the second waveguide is configured to receive light not coupled to the first waveguide; and a structure coupled to the second region of the second waveguide and configured to reduce back-reflections of light from the second region toward the first region.