REFLECTION-ENHANCED PHOTO-DETECTOR

摘要

An integrated optical device includes a photo-detector (such as germanium) optically coupled to an optical waveguide. This photo-detector is deposited on the optical waveguide, and an optical signal propagating in the optical waveguide may be evanescently coupled to the photo-detector. In order to increase the absorption length of the photo-detector, a mirror (such as a distributed Bragg reflection grating) is included in the optical waveguide near the end of the photo-detector. This mirror reflects the optical signal back toward the photo-detector, thereby increasing the absorption of the optical signal by the photo-detector. In addition, absorption may be reduced by using electrical contacts that are electrically coupled to the photo-detector at locations where the optical mode of the optical signal is largely in the underlying optical waveguide, and by using a fingered metal layer to couple to the electrical contacts.

主权项

1. An optical device, comprising:
an optical waveguide configured to convey an optical signal having a wavelength; a photo-detector having a first end and a second end, wherein the photo-detector is disposed on and optically coupled to a surface of a region of the optical waveguide, wherein the photo-detector is configured to convert the optical signal to an electrical signal; and a mirror after and proximate to the second end of the photo-detector, wherein the mirror is in a plane of the optical waveguide, and wherein the mirror is configured to at least partially reflect the optical signal.