On-chip near 100 dB pump filtering using silicon ion implantation.

Area of Science:

• Integrated photonics
• Quantum optics
• Materials science

Background:

• Integrated photonics offers stability and scalability for quantum technologies.
• Challenges in monolithic and hybrid photonic quantum systems hinder demonstrations.
• Filtering high-power pump light from generated photons is crucial for spontaneous parametric down-conversion sources.

Purpose of the Study:

• To report a novel optical filtering technique for integrated photonic quantum systems.
• To address the challenge of pump light suppression in quantum light sources.
• To enable practical on-chip integration of quantum components.

Main Methods:

• Developed silicon nitride (SiN) waveguides with silicon ion implantation.
• Utilized selective absorption of near-visible light for filtering.
• Characterized pump light suppression and insertion loss at telecom wavelengths.

Main Results:

• Achieved nearly 100 dB suppression of 775 nm pump light.
• Demonstrated low insertion loss of approximately 4 dB for 1550 nm telecom C-band light.
• Showcased the potential for significant reduction in insertion loss.

Conclusions:

• The novel SiN waveguide filter effectively suppresses pump light while maintaining low loss for quantum signal photons.
• This technique facilitates the integration of quantum sources, filters, and detectors on a single chip.
• Advances the development of scalable quantum photonic systems for communication, computing, and sensing.