System and Method for an Optical Coupler

摘要

In one embodiment, an optical directional coupler includes an input terminal configured to receive an input optical signal and a first coupler optically coupled to the input terminal, where the first coupler has a first coupling length, and where the first coupler is configured to couple a first portion of the input optical signal to a first optical leg and a second optical portion of the input optical signal to a second optical leg. The optical directional coupler also includes the first optical leg, where the first optical leg is configured to phase shift the first portion of the optical signal to produce a first phase shift signal and the second optical leg, where the second optical leg is configured to phase shift the second portion of the optical signal to produce a second phase shift signal, and where the first phase shift signal has a phase difference relative to the second phase shift signal. Additionally, the optical directional coupler includes a second coupler configured to receive the first phase shift signal and the second phase shift signal and to output a first output optical signal to a first output, where the second coupler has a second coupling length, where a crosstalk of the input optical signal to a second output is below −15 dB for both transverse electrical (TE) polarized light and transverse magnetic (TM) polarized over a wavelength range spanning 40 nm.

主权项

1. An optical directional coupler comprising:
an input terminal configured to receive an input optical signal; a first coupler optically coupled to the input terminal, wherein the first coupler has a first coupling length, and wherein the first coupler is configured to couple a first portion of the input optical signal to a first optical leg and a second optical portion of the input optical signal to a second optical leg, wherein the first optical leg is configured to phase shift the first portion of the optical signal to produce a first phase shift signal, wherein the second optical leg is configured to phase shift the second portion of the optical signal to produce a second phase shift signal, and wherein the first phase shift signal has a phase difference relative to the second phase shift signal; and a second coupler configured to receive the first phase shift signal and the second phase shift signal and to output a first output optical signal to a first output, wherein the second coupler has a second coupling length, wherein a crosstalk of the input optical signal to a second output is below about −15 dB for both transverse electrical (TE) polarized light and transverse magnetic (TM) polarized over a wavelength range spanning about 40 nm.