Collimation testing and calibration using a heterodyne Moiré method

Lissajous figure-based single-frame collimation technique

“…Most of them are based on interferometry [1][2][3][4][5] or on self-imaging techniques [6][7][8][9]. In addition, several techniques have been proposed in the last years [10][11][12][13][14][15]. In particular, several collimation methods based on self-imaging that do not need a lateral displacement of the grating have been proposed, being these devices simple an stable.…”

Phase-shifting lateral shearing interferometry using wedge-plate and interferometric grating

“…Errors in beam collimation may result in severe degradation of system performance. Automated interferogramanalysis-based techniques have been incorporated to improve the measurement characteristics [17][18][19][20][21]. The use of these techniques has increased the performance of the collimation test substantially.…”

“…This corresponds to the 7 × 10 −4 degree divergence/convergence angle change of the optical beam emerging from the collimating lens. Chang et al [19] reported collimation testing and calibration using a heterodyne moiré method. They claimed the value of Δf to be 7 μm.…”