Modal rotation in optical waveguides

摘要

An optical waveguide structure includes a rotator having a dual-layer core. A first layer of the dual-layer core may include a tapering portion. A second layer of the dual-layer core may include a rib portion disposed on the tapering portion. The combination of the rib portion and the tapering portion may receive a pair of optical signals, one being polarized in a TE mode and the other being polarized in a TM mode, and convert them to a pair of TE mode optical signals.

主权项

1. An apparatus comprising:
an optical waveguide structure configured to transmit a pair of optical signals in guided modes, the optical waveguide structure comprising a rotator that comprises a dual-layer core comprising a first layer disposed on a substrate and a second layer disposed on the first layer, wherein the first layer comprises a base portion that inversely tapers from a first end to a second end of the core such that a width of the base portion at the first end is less than the width of the base portion at the second end, and wherein the second layer comprises a rib portion, wherein a width of the rib portion is less than the width of the base portion at the first end and at the second end, and wherein the rotator is configured to:
receive a first optical signal of the pair of optical signals polarized in a first transverse electric (TE) mode and maintain the first optical signal in the first TE mode as the first optical signal propagates through the rotator; andreceive a second optical signal of the pair of optical signals polarized in a second TE mode and convert the second optical signal from being polarized in the second TE mode to being polarized in a transverse magnetic (TM) mode as the second optical signal propagates through the rotator.