Pyramid error in optics refers to an aberration in the shape of an optical surface, particularly in the context of mirrors. It is a type of distortion that can occur when the surface of a mirror deviates from the ideal shape, affecting the performance of the optical system.
The pyramid error is characterized by deviations from the desired surface shape that resemble a pyramid. Specifically, it refers to the height difference between the highest and lowest points on the mirror surface, measured along radial lines extending from the center of the mirror.
Minimizing pyramid error is crucial in optical systems, especially in applications where high precision is required, such as astronomy or high-performance imaging systems. Advanced manufacturing and polishing techniques are employed to achieve the desired surface accuracy and minimize aberrations like pyramid error.