Digital Holography With Improved Resolution by Spatial Sampling of Holograms
In digital Fresnel holography, present specifications of cameras require the incident beams to be quasi-parallel. That implies large speckle grain size and low lateral resolution in reconstructed images. Better lateral resolutions are demonstrated in our work, down to 8 µm, allowing the observation of sub-millimetre objects by digital holography. The experimental set-up built samples the incident light distribution with a definition of 500 pixels mm-1. The maximum acceptable angle is then widened and the hologram recording and reconstruction distances are drastically reduced, as well as the speckle size. The design of dedicated Active Pixel Sensor CMOS cameras is also discussed.
KeywordsLateral Resolution High Spatial Frequency Spatial Sampling Light Distribution Digital Holography
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