Stability and beam divergence of multimode lasers with internal variable lenses

Area of Science:

• Optics and Photonics
• Laser Physics
• Optical Engineering

Background:

• Optical resonators are fundamental components in laser systems and optical instruments.
• Characterizing resonator stability and beam properties is crucial for device performance.
• Internal lenses introduce complexities in resonator analysis beyond simple stability parameters.

Purpose of the Study:

• To comprehensively investigate the properties of optical resonators containing an internal lens.
• To analyze beam characteristics such as diameter, divergence, and waist position.
• To determine regions of stability and low sensitivity to internal lens focal length variations.

Main Methods:

• Utilizing the resonator matrix method for detailed analysis.
• Calculating equivalent g-parameters to define stability regions.
• Evaluating correlations between beam parameters, lens position, and focal length.

Main Results:

• Identified key beam parameters (diameter, divergence, waist position) and their dependence on the internal lens.
• Determined stability regions influenced by the variable focal length lens.
• Located and evaluated regions of low sensitivity to focal length changes.
• Presented numerical results for specific resonator configurations.

Conclusions:

• The resonator matrix method provides a more complete analysis than g-parameters alone for resonators with internal lenses.
• Understanding parameter correlations is essential for designing stable and predictable optical resonators.
• Experimental validation confirms the predicted regions of low sensitivity to focal length variations.