Polarization-independent single-photon switch based on a fiber-optical Sagnac interferometer for quantum...

Area of Science:

• Quantum optics
• Photonics
• Quantum information science

Background:

• Future quantum networks require efficient single-photon routing.
• Existing optical switches often lack polarization independence, limiting applications.

Purpose of the Study:

• To implement a polarization-independent optical switch for dynamic single-photon routing.
• To demonstrate the switch's performance using commercial off-the-shelf components.

Main Methods:

• A fiber-optical Sagnac interferometer was designed and constructed.
• Two fast electro-optical telecom phase modulators were integrated into the Sagnac loop.
• The modulators were configured to act on orthogonal polarization components of single photons.

Main Results:

• The optical switch demonstrated polarization-independent single-photon routing.
• An average extinction ratio exceeding 19 dB was achieved between the switch outputs.
• The experimental setup exclusively used commercially available components.

Conclusions:

• The developed Sagnac interferometer-based optical switch is a viable component for future quantum networks.
• The polarization-independent design and use of COTS components facilitate integration with existing optical communication systems.