Visible light photonic integrated Brillouin laser

Area of Science:

• Photonics and Optical Engineering
• Quantum Technologies
• Atomic, Molecular, and Optical (AMO) Physics

Background:

• Narrow linewidth visible light lasers are essential for advancements in atomic, molecular, and optical (AMO) physics, including atomic clocks, quantum computing, and sensing.
• Stimulated Brillouin scattering (SBS) offers a promising pathway for creating highly coherent, on-chip visible light lasers.

Purpose of the Study:

• To demonstrate a visible light photonic integrated Brillouin laser operating at 674 nm.
• To overcome existing challenges in achieving SBS in the visible spectrum for integrated photonic devices.

Main Methods:

• Fabrication of silicon nitride/silica all-waveguide resonators optimized for visible light.
• Characterization of waveguide losses, resonator quality factor (Q), Stokes frequency shift, and gain bandwidth.
• Demonstration of stimulated Brillouin scattering (SBS) for laser emission.

Main Results:

• Achieved a visible light photonic integrated Brillouin laser with 674 nm emission.
• Reported a low optical threshold of 14.7 mW (4.92 mW μm⁻²) and an ultra-narrow linewidth of 269 Hz.
• Overcame previous limitations with 1 dB/meter waveguide losses, a 55.4 million Q factor, a 25.110 GHz Stokes shift, and a 290 MHz gain bandwidth.

Conclusions:

• The developed integrated ultra-narrow linewidth visible wavelength SBS laser represents a significant advancement.
• This technology paves the way for compact quantum and atomic systems.
• Enables the implementation of more complex AMO-based physics and experiments.