Scaling laws for cw 337-microm HCN waveguide lasers

Area of Science:

• Physics
• Laser Technology
• Optics

Background:

• Continuous-wave (cw) 337-micrometer lasers are crucial for various applications.
• Understanding the relationship between laser parameters and physical dimensions is essential for optimization.
• Previous studies may not have fully explored the impact of tube diameter on laser performance.

Purpose of the Study:

• To empirically determine the relationship between gain, saturation intensity, and tube diameter in optimized cw 337-micrometer lasers.
• To derive an expression for waveguide laser power as a function of geometrical parameters, losses, and coupling.
• To identify the optimal tube diameter for maximum laser power output.

Main Methods:

• Empirical measurements of gain and saturation intensity in relation to tube diameter.
• Derivation of a theoretical expression for waveguide laser power.
• Experimental validation using three waveguide lasers with varying lengths (1-m, 2-m, 3-m).

Main Results:

• Gain and saturation intensity vary inversely with tube diameter.
• Laser power is strongly dependent on tube diameter, with a clear maximum at optimized coupling.
• Optimal diameter is determined solely by tube length and losses.
• Measured powers of 30 mW, 100 mW, and 170 mW were achieved for 1-m, 2-m, and 3-m lasers, respectively.

Conclusions:

• The study provides a clear understanding of how geometrical parameters influence 337-micrometer waveguide laser performance.
• Optimized waveguide lasers demonstrate competitive power output compared to optically pumped submillimeter lasers.
• The derived expressions and empirical findings can guide the design of more efficient submillimeter waveguide lasers.