Calculation model of the slightly misaligned optical multi-pass cell based on the augmented 4*4 matrix

Abstract A novel augmented 4*4 matrix model for the slightly misaligned optical multi-pass cell whose spherical mirrors are not coaxial due to the presence of small misaligned angle and linear displacement of the spherical mirrors is reported. The augmented 4*4 matrix model is proposed to describe the behavior of light rays in the misaligned optical multi-pass cell. By augmented 4*4 matrix model, a series of numerical calculation are performed to validate that the incident light ray remains unchanged, and then retrace the same spot pattern. It is found that the set of spot patterns from numerical analysis displays a displacement on the surface of the mirror and the misaligned optical elements increase the loss and reduce pass counts. More importantly, the augmented 4*4 matrix model can be used to analyze the misalignment sensitivity of the optical multi-pass cells.