MATLAB Code Implementation for Laser Resonator Simulation

In laser physics research, resonator simulation is a critical component for understanding laser performance. MATLAB enables efficient simulation of resonator characteristics with different geometric configurations, primarily focusing on three typical structures: linear cavities, circular cavities, and ring cavities.

Linear Cavity Simulation The linear cavity represents the simplest resonator structure, consisting of two parallel mirrors. MATLAB facilitates analysis of intracavity optical field distribution through transmission matrix modeling, particularly solving mode characteristics using wave equations. By configuring parameters such as cavity length and mirror curvature radius, resonant frequencies and mode distributions can be computed. Implementation typically involves defining mirror reflectance matrices and propagating field vectors through matrix multiplication operations.

Circular Cavity Simulation Circular cavities (e.g., confocal cavities or spherical mirror cavities) require more complex mathematical descriptions. MATLAB's numerical tools can solve wave equations under circular symmetric boundary conditions to simulate Gaussian beam propagation characteristics. Through adjustments of mirror curvature and cavity length, beam quality can be optimized while suppressing higher-order transverse modes. Key functions often include Bessel function implementations for cylindrical coordinates and eigenmode solvers for stability analysis.

Ring Cavity Simulation Ring cavities are commonly used in high-power laser systems, where their closed optical path structures demand precise simulation of multiple round-trip beam propagation. MATLAB enables analysis of ring cavity stability using ray tracing methods or split-step Fourier techniques, while evaluating how loss mechanisms affect laser output. Code implementation typically involves iterative propagation algorithms with boundary condition checks and loss coefficient integration at each round-trip.

By properly setting boundary conditions and initial parameters, MATLAB programs can visually demonstrate intensity distributions and phase characteristics of different resonator modes, providing reliable simulation foundations for laser design. The code structure generally includes parameter initialization blocks, propagation calculation loops, and visualization functions using contour plots or 3D surface displays.