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DFG-based mid-IR tunable source with 0.5 mJ energy and a 30 pm linewidth
Optics Letters
|October 1, 2020
Summary
We developed a tunable mid-infrared laser system using difference frequency generation (DFG). This system achieves narrow-linewidth radiation for high-resolution spectroscopy applications.
Area of Science:
- Optics and Photonics
- Laser Physics
- Nonlinear Optics
Background:
- Mid-infrared (mid-IR) radiation is crucial for various spectroscopic techniques.
- Generating tunable, narrow-linewidth, and high-energy mid-IR sources remains a challenge.
Purpose of the Study:
- To report on a novel laser system for generating tunable mid-IR radiation.
- To demonstrate the system's capability for high-resolution spectroscopy.
Main Methods:
- Difference frequency generation (DFG) using a lithium thioindate (LiInS2) nonlinear crystal.
- Employing nanosecond pulses from single-frequency Nd:YAG (1064 nm) and Cr:forsterite (1262 nm) lasers.
- Utilizing single-pass and double-pass configurations for the nonlinear crystal.
Main Results:
- Achieved tunable, narrow-linewidth mid-IR radiation at 6.8 µm.
- Obtained 205 µJ energy in a single-pass configuration.
- Increased energy output to 540 µJ with a double-pass configuration.
Conclusions:
- The developed DFG laser system provides high-energy, narrow-linewidth mid-IR radiation.
- The system is suitable for photon-hungry, high-resolution spectroscopy in the mid-IR region.
- LiInS2 crystal is effective for DFG in this spectral range.
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