Seminar on Optical Isolator: Application to Photonic Integrated Circuits

Optical active devices fail to operate in a desired manner, when unwanted reflections are launched into them. An optical isolator plays an essential role in protecting optical devices from unwanted reflections. Commercially available optical isolators based on a magneto-optic Faraday effect, which are provided with optical fiber and optical beam interfaces, are hard to be integrated with other optical devices. In case of waveguide isolators, it is quite unrealizable to use a rotation of polarization, because the precise control of waveguide birefringence is needed. Several approaches have been developed to avoid the precise control of waveguide geometry, like a nonreciprocal radiation and a nonreciprocal loss isolator. An interferometric waveguide isolator, which uses a nonreciprocal phase shift provided by the first-order magneto-optic effect, has the advantages of a single polarization operation and a wide operational wavelength range. Also, the interferometric isolator is realizable in several waveguide platforms by using a magneto-optic material in a cladding layer. To achieve this, we developed a direct bonding technique of magneto-optic garnet on III-V compound semiconductors and silicon waveguides. In this talk, the integration of optical isolators will be addressed, which includes a non-magneto-optic approach. 

reference :http://www.eng.monash.edu.au