We propose a novel highly sensitive wave front detection method for a quick check of a flat wave front by taking advantage of a non-zero-order pi phase plate that yields a non-zero-order diffraction pattern. When a light beam with a flat wave front illuminates a phase plate, the zero-order intensity is zero. When there is a slight distortion of the wave front, the zero-order intensity increases. The ratio of first-order intensity to that of zero-order intensity is used as the criterion with which to judge whether the wave front under test is flat, eliminating the influence of background light. Experimental results demonstrate that this method is efficient, robust, and cost-effective and should be highly interesting for a quick check of a flat wave front of a large-aperture laser beam and adaptive optical systems.
© 2005 Optical Society of America
(010.7350) Atmospheric and oceanic optics : Wave-front sensing
(120.4640) Instrumentation, measurement, and metrology : Optical instruments
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
Hongxin Luo, Changhe Zhou, and Hua Zou, "Highly sensitive wave-front sensor with a non-zero-order phase plate," Appl. Opt. 44, 4654-4658 (2005)