Non-contact measurement method for blaze angle of blazed transmission grating based on total reflection

Blaze angle is definitely a crucial parameter of blazed transmission gratings, which significantly affects the diffraction efficiency of gratings. In this paper, we observed a phenomenon that total reflection causes the grating energy distribution to change significantly within a small angle range and can be used to measure the blaze angle. We conducted experiments and simulations with 632.8 nm and 457.0 nm sources to verify this phenomenon. The experimental results and correlation simulation analysis showed that this phenomenon occurs regardless of the wavelength and polarization state. For the grating with a blaze angle of 31.70% in the case of 632, 8 nm or 457 nm light sources, the blaze angle tested by our method is 31.72 degrees or 31.73 degrees. Meanwhile, the experiment also confirmed that the method of measuring the blaze angle of the grating based on this phenomenon is feasible. After analysis, the measurement errors of the blaze angle are less than 0.03 degrees. Using this method, we can more easily and conveniently measure the blaze angle of the grating, which is more effective, easy to implement and will not cause damage to the grating.