Pulse shaping in a midwave-IR OPCPA for multi-µJ few-cycle pulse generation at 12 µm via DFG

Area of Science:

• Nonlinear Optics
• Ultrafast Lasers
• Mid-Infrared (mid-IR) Photonics

Background:

• Generating high-energy, few-cycle pulses in the mid-IR (beyond 4 µm) is crucial for advanced spectroscopy and nonlinear optics.
• Existing pulse shaping technologies in this spectral region are insufficient for precise higher-order phase control.
• Optical Parametric Chirped Pulse Amplification (OPCPA) is a promising technique for achieving high-energy ultrashort pulses.

Purpose of the Study:

• To investigate novel dispersion management techniques for mid-IR OPCPA systems.
• To enable the generation of high-energy pulses at 12 µm through difference frequency generation (DFG).
• To overcome limitations in higher-order phase control for few-cycle pulse generation in the mid-IR.

Main Methods:

• Development and testing of alternative mid-IR pulse shaping methods, including a germanium-prism pair.
• Implementation of a sapphire-prism-based Martinez compressor for pulse compression.
• Exploration of bulk compression limits in Silicon (Si) and Germanium (Ge) for multi-millijoule (mJ) pulse energies.

Main Results:

• Demonstrated feasibility of germanium-prism pairs and sapphire-prism Martinez compressors for mid-IR pulse shaping.
• Investigated the potential for generating high-energy 12 µm pulses via DFG using optimized OPCPA signal and idler pulses.
• Characterized the performance and limitations of bulk materials (Si, Ge) for high-energy pulse compression in the mid-IR.

Conclusions:

• Alternative pulse shaping techniques offer viable solutions for dispersion management in mid-IR OPCPA.
• The proposed methods pave the way for generating high-energy few-cycle pulses beyond 4 µm, extending to 12 µm.
• Understanding bulk compression limits is essential for scaling to multi-mJ pulse energies in mid-IR systems.