High-power tunable dual-wavelength diode laser with a composite external cavity

Area of Science:

• Optics and Photonics
• Laser Physics
• Materials Science

Background:

• Tunable lasers are crucial for applications requiring precise wavelength control.
• Achieving stable, high-power dual-wavelength output with a narrow frequency difference presents significant challenges.

Purpose of the Study:

• To propose and demonstrate a novel high-power tunable dual-wavelength laser architecture.
• To investigate the performance characteristics of the proposed laser system, including its tuning range, output power, and spectral stability.

Main Methods:

• A composite external cavity design utilizing a holographic grating and a volume Bragg grating.
• Characterization of the dual-wavelength output across a tunable frequency difference range.

Main Results:

• Demonstrated a tunable frequency difference from 0.41 THz to 3.89 THz.
• Achieved a maximum output power of 2.1 W at a frequency difference of 1.86 THz.
• Maintained a side-mode suppression ratio exceeding 29 dB and a power difference between wavelengths as low as 0.10%.

Conclusions:

• The proposed holographic grating and volume Bragg grating composite external cavity architecture enables high-power, tunable dual-wavelength operation.
• The system exhibits excellent spectral stability and intensity balance between the two output wavelengths.
• This technology holds promise for applications in spectroscopy, sensing, and optical communications.