Ultrafast 10 mJ, 100 W laser system featuring a directly laser written depolarization compensation element

Area of Science:

• Laser Physics
• Nonlinear Optics
• Materials Science

Background:

• Optical Parametric Chirped Pulse Amplification (OPCA) systems require high-energy, high-average-power laser sources for pumping.
• Existing laser technologies often face limitations in terms of compactness, cost-effectiveness, or performance for these demanding applications.

Purpose of the Study:

• To demonstrate a novel, compact, and cost-effective picosecond laser system.
• To achieve high pulse energy and high average power suitable for pumping OPCPA systems.
• To optimize beam quality and minimize optical losses within the laser system.

Main Methods:

• A hybrid laser architecture combining a fiber seed laser and free-space end-pumped Ytterbium-doped Yttrium Aluminum Garnet (Yb:YAG) amplifiers was employed.
• Output pulses were compressed to 1 picosecond (ps) duration.
• Spatial filtering was utilized to enhance beam quality, characterized by the M² parameter.
• A custom-designed silica glass spatially variable wave plate, fabricated using direct laser writing, was incorporated to mitigate depolarization losses.

Main Results:

• The laser system achieved a record high pulse energy at an average power level of 100 W.
• The output beam quality was measured with an M² value of 1.3, subsequently improved to 1.07 via spatial filtering.
• Depolarization losses were significantly reduced from 12% to 5% through the use of the direct laser-written wave plate.

Conclusions:

• The developed picosecond laser system offers a compact and cost-effective solution for OPCPA pumping applications.
• The system demonstrates state-of-the-art performance in terms of pulse energy and average power.
• Advanced optical components and techniques, such as direct laser writing for wave plates, are effective in optimizing laser performance and minimizing losses.