Remote laboratory for digital holographic metrology

Advances in information technology open up the potential of combining optical systems with net based infrastructures, allowing for remote inspection and virtual metrology. In this paper, we report our recent work on building a remote laboratory for digital holographic metrology. We describe the architecture and the techniques involved in setting up the remote controlling metrology system. Further consideration will be given to the integration into an advanced infrastructure for remote experimentation, data storage and publication. Some other important issues such as information security will not be addressed

Two-wavelength digital holography through fog

Interferometric detection enables the acquisition of the amplitude and phase of the optical field. By making use of the synthetic wavelength as a computational construct arising from digital processing of two off-axis digital holograms, it is possible to identify the shape of an object obscured by fog and further increase the imaging range due to the increased sensitivity in coherent detection. Experiments have been conducted inside a 27 m long fog tube filled with ultrasonically generated fog. We show the improved capabilities of synthetic phase imaging through fog and compare this technique with conventional active laser illumination imaging