Widely tunable red-edge laser based on intra-cavity second harmonic generation driven by BaGa₄Se₇ optical parametric...

Area of Science:

• Optics and Photonics
• Remote Sensing Technology

Background:

• Red-edge lasers (670-780 nm) are crucial for remote sensing, particularly in vegetation monitoring, crop identification, and precision agriculture.
• Tunable lasers are essential for optimizing spectral measurements in these applications.

Purpose of the Study:

• To develop a widely tunable red-edge laser system.
• To enhance remote sensing capabilities through improved laser technology.

Main Methods:

• Utilized a doubly resonant optical parametric oscillator (OPO) with intra-cavity second harmonic generation (SHG).
• Employed a BaGa4Se7 OPO pumped by a double-pass system and a KTiOPO4 crystal for SHG.
• Investigated both intra-cavity and extra-cavity configurations for comparative analysis.

Main Results:

• Achieved broadband tunable output from 648.12 nm to 799.42 nm.
• Delivered output energy exceeding 1 mJ over a 150 nm tuning range.
• Measured spectral linewidth below 0.3 nm.
• Demonstrated reduced threshold and improved conversion efficiency with the intra-cavity configuration.

Conclusions:

• The developed laser system provides a wide tuning range across the entire red-edge spectrum.
• The intra-cavity design offers significant advantages over extra-cavity setups.
• This technology is poised to advance remote sensing applications in agriculture and environmental monitoring.