A procedure for obtaining real-time holographic moirélike patterns and measuring small angles is proposed. Two rotated sinusoidal phase gratings are superposed, and the result represents a promising technique for making small-angle measurements in metrological applications. The experiments are performed with a diffusion-only recording mechanism in the photorefractive crystal Bi<sub>12</sub>TiO<sub>20</sub> illuminated by λ = 0.633 μm light from a He–Ne laser.
© 2000 Optical Society of America
(090.7330) Holography : Volume gratings
(120.2880) Instrumentation, measurement, and metrology : Holographic interferometry
(120.4120) Instrumentation, measurement, and metrology : Moire' techniques
Paulo Acioly Marques dos Santos, Luis Carlos da Silva Nunes, and Inaya Corrêa, "Dynamic Holographic Moiré Patterns in Photorefractive Bi12 TiO20 and Small-Angle Measurements," Appl. Opt. 39, 4524-4528 (2000)