Demonstration of an optical isolator with a semiconductor guiding layer that was obtained by use of a nonreciprocal phase shift

Abstract

We present the experimental study of an optical isolator with a semiconductor guiding layer that was obtained by use of a nonreciprocal phase shift. The isolator is equipped with an optical interferometer composed of tapered couplers, nonreciprocal phase shifters, and a reciprocal phase shifter. The nonreciprocal phase shifter was constructed by wafer direct bonding between the semiconductor guiding layer and the magneto-optic cladding layer. The isolator, designed for the 1.55-mum wavelength, was fabricated to investigate the characteristics of each component. By applying an external magnetic field to the nonreciprocal phase shifter, we achieved an isolation ratio of approximately 4.9 dB in the interferometric isolator.

Silicon ring isolators with bonded nonreciprocal magneto-optic garnets

“…Proper Mach-Zehnder Interferometer (MZI) design with nonreciprocal phase shift generates constructive interference for forward light and destructive interference for backward light to realize optical isolation. The MZI optical isolators have been demonstrated on both III-V and silicon platforms [6,7].…”

11.4 dB isolation on an amplifying AlGaInAs/InP optical waveguide isolator

“…The integration with III-V host material however remains an issue. The best reported result demonstrated isolation not higher than 5dB in a device of several millimeters long [2].…”

Comparison of Integrated Optical Phase Shifters Designed in Different Regime

“…Mach-Zehnder interferometer [1,2], optical isolator [3,4], arrayed waveguide grating(AWG) [5,6], and optical mixer [7,8]. The structure selection of phase shifter plays a key role in optimizing the performance of integrated optical devices.…”