Asymptotically fault-tolerant programmable photonics.

Area of Science:

• Photonics
• Integrated Optics
• Quantum Computing

Background:

• Component errors in programmable photonic circuits hinder scalability.
• The standard Mach-Zehnder interferometer (MZI) cannot perfectly achieve the cross state, limiting circuit fidelity.

Purpose of the Study:

• To introduce novel circuit architectures that overcome limitations in programmable photonic circuits.
• To enable the development of arbitrarily large-scale programmable photonic circuits by addressing MZI cross-state errors.

Main Methods:

• Proposed a 3-splitter MZI mesh architecture for generic errors.
• Introduced a broadband MZI+Crossing design for correlated errors.
• Demonstrated perfect realization of the cross state in modified architectures.

Main Results:

• Modified architectures allow perfect cross-state realization, preventing matrix fidelity degradation.
• Achieved scalability to arbitrarily large meshes without fidelity loss.
• Proposed designs are more compact and do not require additional phase shifters compared to existing schemes.

Conclusions:

• The novel architectures remove a critical barrier to the development of very-large-scale programmable photonic circuits.
• These designs facilitate progressive self-configuration and improved performance.
• Enables advancements in integrated optics and related fields.