2.7 μm backward wave optical parametric oscillator source for CO₂ spectroscopy.

Area of Science:

• Laser Physics
• Spectroscopy
• Optical Engineering

Background:

• Developing compact and stable light sources is crucial for gas spectroscopy.
• Backward wave optical parametric oscillators (BWOPOs) offer unique properties for generating specific wavelengths.
• Existing methods often require complex stabilization for precise spectral output.

Purpose of the Study:

• To demonstrate a novel 2.7 µm light source for CO2 and H2O vapor spectroscopy.
• To characterize the performance of a BWOPO for spectroscopic applications.
• To explore the potential of BWOPOs for differential absorption lidar (DIAL) systems.

Main Methods:

• Utilizing the backward propagating wave of a BWOPO.
• Employing a multi-longitudinal mode Q-switched pump laser at 1030 nm.
• Developing novel methods for linewidth and wavelength stability measurements using ambient air.

Main Results:

• Demonstrated a novel 2.7 µm light source with a central output at 2712 nm.
• Achieved a temperature tuning rate of -1.77 GHz/K and an output pulse energy of 2.3 µJ.
• Measured a narrow output linewidth of 43 pm and a stability of 65 MHz without active stabilization.

Conclusions:

• BWOPOs provide a robust and inherently stable platform for spectroscopic light sources.
• The demonstrated 2.7 µm source is suitable for CO2 and H2O spectroscopy.
• This technology holds significant potential for advancing differential absorption lidar (DIAL) systems.