Widefield two laser interferometry.
Open Access
- 23 October 2014
- journal article
- Published by Optica Publishing Group in Optics Express
- Vol. 22 (22), 27094-27101
- https://doi.org/10.1364/oe.22.027094
Abstract
A novel system has been developed that can capture the wide-field interference pattern generated by interfering two independent and incoherent laser sources. The interferograms are captured using a custom CMOS modulated light camera (MLC) which is capable of demodulating light in the megahertz region. Two stabilised HeNe lasers were constructed in order to keep the optical frequency difference (beat frequency) between the beams within the operational range of the camera.This system is based on previously reported work of an ultrastable heterodyne interferometer [Opt. Express 20, 17722 (2012)]. The system used an electronic feedback system to mix down the heterodyne signal captured at each pixel on the camera to cancel out the effects of time varying piston phase changes observed across the array. In this paper, a similar technique is used to track and negate the effects of beat frequency variations across the two laser pattern. This technique makes it possible to capture the full field interferogram caused by interfering two independent lasers even though the beat frequency is effectively random.As a demonstration of the system's widefield interferogram capture capability, an image of a phase shifting object is taken using a very simple two laser interferometer.Keywords
This publication has 20 references indexed in Scilit:
- Widefield heterodyne interferometry using a custom CMOS modulated light camera.Optics Express, 2011
- Real-time heterodyne speckle pattern interferometry using the correlation image sensorApplied Optics, 2010
- Two-photon interference with thermal lightPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2005
- Full-field heterodyne interference microscope with spatially incoherent illuminationOptics Letters, 2004
- Real-Time, Micrometer Depth-Resolved Imaging by Low-Coherence Reflectometry and a Two-Dimensional Heterodyne Detection TechniqueJapanese Journal of Applied Physics, 2000
- Video-rate optical low-coherence reflectometry based on a linear smart detector array.Optics Letters, 2000
- Two-wavelength laser interferometry using superheterodyne detectionOptics Letters, 1988
- Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometryJournal of the Optical Society of America, 1982
- High-performance real-time heterodyne interferometryApplied Optics, 1979
- Digital Wavefront Measuring Interferometer for Testing Optical Surfaces and LensesApplied Optics, 1974