Zinc-indiffused MgO:PPLN waveguides for blue/UV generation via VECSEL pumping

Area of Science:

• Nonlinear optics
• Quantum optics
• Materials science

Background:

• Periodically poled lithium niobate (PPLN) waveguides are crucial for nonlinear optical frequency conversion.
• Compact, efficient pump sources are needed to miniaturize nonlinear optical systems.
• Vertical external-cavity surface-emitting lasers (VECSELs) offer potential as compact, high-power laser sources.

Purpose of the Study:

• To design and characterize a zinc-indiffused PPLN ridge waveguide for second-harmonic generation (SHG).
• To investigate the use of a novel broadband near-infrared VECSEL as a pump source for nonlinear waveguides.
• To demonstrate a compact, integrated nonlinear optical system for generating deep ultraviolet (DUV) light.

Main Methods:

• Fabrication of a zinc-indiffused PPLN ridge waveguide.
• Development of a VECSEL with an intracavity birefringent filter for spectral control.
• Characterization of the VECSEL output power and spectral properties.
• Pumping the nonlinear waveguide with the VECSEL to achieve SHG at ~390 nm.

Main Results:

• Demonstrated a VECSEL with 500 mW output power and spectrally narrowed output.
• Achieved first-time VECSEL-pumping of a nonlinear waveguide.
• Generated 1 mW of ~390 nm light via SHG from 780 nm fundamental light.
• Showcased the potential for increased efficiency and size reduction.

Conclusions:

• The VECSEL-pumped PPLN waveguide system represents a significant step towards compact DUV light generation.
• This integrated approach offers a promising alternative to bulky commercial laser systems for nonlinear frequency conversion.
• Further optimization can lead to higher power and improved efficiency for miniaturized nonlinear optical sources.