Tolerance Evaluation for Light Source Position in Paraboloidal Mirror Collimators

An approximate analytical relationship between light source position having axial and lateral defocusing and the reflective wavefront configuration is deduced. Tolerance evaluation equations for light source position with planar and spherical reference wavefronts are then given. Numerical examples show that the tolerance would be at the order of wavelength for planar reference wavefront, and would be relaxed to about 0.5mm if spherical reference wavefront is acceptable .