Duration-tunable picosecond source at 560  nm with watt-level average power

Area of Science:

• Optics and Photonics
• Laser Physics
• Nonlinear Optics

Background:

• Development of high-power, tunable laser sources is crucial for scientific research and technological applications.
• Existing sources often face limitations in terms of tunability, power, or compactness.
• Efficient generation of visible light from near-infrared sources remains an active area of research.

Purpose of the Study:

• To demonstrate a compact and turn-key tunable pulse source at 560 nm.
• To achieve high average power and near diffraction-limited beam quality.
• To investigate efficient second-harmonic generation for visible light production.

Main Methods:

• Utilized efficient second-harmonic generation (SHG) in a periodically poled lithium tantalate (PPLT) crystal.
• Employed a fiber-integrated Raman amplifier operating at 1120 nm, pumped by a duration-tunable ytterbium master-oscillator power-fiber amplifier.
• Seeded the Raman amplifier with a continuous-wave distributed-feedback (DFB) laser diode at 1120 nm.

Main Results:

• Demonstrated a 560 nm pulse source tunable in duration from 50 ps to 2.7 ns.
• Achieved >1 W of average power with near diffraction-limited beam quality.
• Obtained a pulse energy of up to 765 nJ with a 25% conversion efficiency from the ytterbium fiber pump.

Conclusions:

• A compact and turn-key architecture for generating high peak-power radiation at 560 nm has been successfully demonstrated.
• The developed system offers efficient SHG and tunable pulse characteristics.
• This source provides a valuable tool for applications requiring high-quality visible light pulses.