Setting sensitivity in Talbot interferometry with modified gratings

General analyses on effects of nonparallel grating planes in Talbot interferometry

“…Ingeneral, the angle S is set by experimenter [4,9], therefore, we will no longer discuss the effect of the angle here.…”

“…TaIbot interferometry has been widely used to detect many kinds of information, such as beam collimation checking [1][2][3][4], measurement ofthe focal length ofa lens and so on [5][6][7][8][9], by means ofthe deformation ofthe moire fringes generated by the two gratings. Because the moire fringes are sensitively affected by the inclination between the two grating planes, it is important to study the effects of the nonparallel grating planes on measurements in Talbot interferometry.…”

Collimation Testing Using Two-Wave Mixing in Photorefractive Crystal

“…The above equation can also be expressed in terms of diffracted and incident beams as [I8J, ,,= I diffracted Iincidenl (10) It can be seen that the expression for diffraction efficiency given by Eq. (9) is a function of absorption coefficient a (O.5/cm for Bi'2 TiO~, and d the thickness of the PR crystal.…”

“…Collimation of a laser beam can be tested by various methods [1][2][3][4][5][6][7][8][9][10][11]. Most of these methods are based either on self-imaging or inteferometric techniques [3,5].…”

“…If the pinhole is not located at the focus of the lens, the resulting beam is slightly divergent or convergent and fringes will appear and when the pinhole is at the focus of the lens there will not be any fringes at the detector plane. Later these methods were modified by Kothiyal and Sirohi [8,91 and Kothiyal et al [10] incorporating a self-referencing technique. A brief review on self-referencing collimating testing was reported by Sriram et al in 1993 [11].…”