Broad-band plasmonic isolator compatible with low-gyrotropy magneto-optical material

Area of Science:

• Photonics
• Materials Science
• Nanotechnology

Background:

• Integrating optical isolators into photonic circuits presents a significant technological challenge.
• Existing solutions often require complex fabrication or specialized materials, hindering widespread adoption.

Purpose of the Study:

• To propose a novel concept for broadband optical isolation.
• To enable the development of non-reciprocal devices using readily available composite materials.
• To overcome the limitations of low-gyrotropy materials in optical isolation.

Main Methods:

• Exploiting coupled mode asymmetry in magnetoplasmonic slot waveguides.
• Utilizing the separation of back-and-forth light paths.
• Numerical simulations to validate the proposed structure.

Main Results:

• Achieved an isolation ratio exceeding 18 dB over a broad bandwidth (tens of nanometers).
• Demonstrated low insertion losses of approximately 2 dB.
• Validated the effectiveness of the proposed structure with suitable absorbers.

Conclusions:

• The proposed concept offers a viable solution for broadband optical isolation.
• This approach facilitates the integration of non-reciprocal devices using composite materials.
• Opens new avenues for advanced photonic circuit functionalities.