Ultracompact optical switch using a single semisymmetric Fano nanobeam cavity

Area of Science:

• Photonics
• Optical Engineering
• Materials Science

Background:

• Waveguide-cavity systems are crucial for integrated photonics.
• Traditional structures face limitations in insertion loss and footprint.
• Fano resonances offer unique optical properties for device design.

Purpose of the Study:

• To propose and analyze a generalized four-port waveguide-cavity system.
• To experimentally demonstrate an ultracompact optical switch using this system.
• To achieve high drop port transmission and low insertion loss.

Main Methods:

• Theoretical analysis of a semisymmetric Fano structure.
• Experimental implementation using a silicon-based photonic crystal nanobeam cavity (PCNC).
• Characterization of optical switch performance, including insertion loss and footprint.

Main Results:

• Demonstration of an ultracompact crossbar optical switch.
• Achieved a low insertion loss of 1.5 dB in the drop port (cross state).
• Observed significantly lower insertion loss compared to traditional non-Fano structures (8.5 dB).
• Device features a high quality factor, small mode volume, and an ultracompact footprint of 14 µm².

Conclusions:

• The proposed PCNC switch with a semisymmetric Fano structure offers superior performance.
• This technology has potential for increasing integration and reducing energy consumption in on-chip optical systems.
• The novel Fano structure enables efficient and compact optical switching solutions.