High-power, continuous-wave, solid-state, single-frequency, tunable source for the ultraviolet.

Area of Science:

• Laser physics
• Nonlinear optics
• Quantum optics

Background:

• Development of compact, high-power, tunable ultraviolet (UV) laser sources is crucial for numerous scientific and industrial applications.
• Existing UV sources often lack tunability, sufficient power, or compactness, limiting their widespread use.

Purpose of the Study:

• To report the development of a novel, compact, high-power, continuous-wave, single-frequency UV source.
• To achieve extended wavelength tunability in the UV range using a specific nonlinear optical process.

Main Methods:

• The device utilizes single-pass, intracavity, second-harmonic-generation (SHG) of signal radiation from a singly resonant optical parametric oscillator (SRO).
• A multigrating MgO-doped periodically poled stoichiometric lithium tantalate (MgO:sPPLT) crystal was employed in the SRO, pumped by green light.
• Frequency doubling was achieved using a bismuth borate (BIBO) crystal to generate UV radiation.

Main Results:

• The SRO was continuously tuned across 710.7-836.3 nm (signal) and 2115.8-1462.1 nm (idler), with maximum idler power of 1.9 W.
• UV generation covered 355.4-418.2 nm with continuous tuning over 62.8 nm.
• Maximum single-frequency UV power reached 770 mW at 398.28 nm with a Gaussian beam profile, and >260 mW over 95% of the tuning range.

Conclusions:

• The developed system provides a compact, high-power, tunable, single-frequency UV source.
• The demonstrated approach enables extended wavelength tunability in the UV spectrum.
• Further extension to lower UV wavelengths is feasible by optimizing SRO operation parameters.