A novel method for collimating beam detection based on total internal reflection

The collimated beam has various applications in the optical test and optical instrument calibrating.A novel method based on the total internal reflection for testing light collimation is put forward in this paper.The collimation of the beam is achieved by detecting the intensity distribution of the beam spot on the detector,before which the total internal reflection happens twice by the prism.And a beam contracting unit which is useful for improving the sensitivity of the detection system is introduced.The factors that affect the precision are discussed and the theoretical analysis is done.The experimental results show that a precision below 5″ can be achieved.