Widely tunable and narrow-linewidth violet lasers enabled by UV-transparent materials

Area of Science:

• Photonics
• Quantum Technology
• Laser Physics

Background:

• Photonic integration of ultraviolet (UV) lasers is crucial for next-generation ion traps, optical clocks, and quantum computing.
• Current integrated waveguide materials limit the integration of highly coherent UV lasers.

Purpose of the Study:

• To demonstrate the first integrated, extended cavity diode laser using solely UV-transparent materials.
• To overcome the material transparency limitations in current integrated photonic devices for UV applications.

Main Methods:

• Integration of aluminum oxide waveguide circuits with gallium nitride amplifiers.
• Development of an extended cavity diode laser architecture.
• Demonstration of mode-hop-free tuning to a Strontium (Sr) transition frequency.

Main Results:

• Achieved milliwatt-level on-chip output power in the UV range.
• Record-low intrinsic laser linewidth of approximately 300 kHz.
• Demonstrated side-mode suppression exceeding 43 dB.
• Successful mode-hop-free tuning to a Sr-transition frequency.

Conclusions:

• The developed integrated laser is viable for UV applications, overcoming previous material limitations.
• This technology enables a new class of integrated UV lasers for ion traps, optical clocks, and quantum computing.
• The results pave the way for miniaturized and scalable photonic systems operating in the UV spectrum.