Session Index

We introduce the analyzation method of volume holographic optical elements. Accordingly, we build up the optical models for different volume holographic optical elements. We improve the holographic data storage system based on the proposed optical models, and further extend the application to opposite virtual objective and lens-less digital holography.

 

A 3D shape measurement system using a volume hologram and an endoscope is presented. It projects a binary-encoded fringe pattern onto the inspected object, and employs an endoscope to observe the projected fringes. Fringes on the obtained image are deformed by the surface profile, and consequently are analyzable to retrieve the 3D shape. The binary-encoded pattern provides additional information to identify the fringe order. Hence surfaces with depth discontinuities can be discerned without ambiguity. The binary-encoded fringe pattern is produced by launching incoherent waves into the volume hologram. The wavelength selectivity makes the diffracted pattern not much blurred by incoherent illumination. The size of the hologram is compact and tiny. Thus, the hologram reconstructs the diffracted pattern with a large depth of focus. Only one shot measurement is needed for image processing. To inspect a dynamic object using an endoscope inside a body cavity is desirable.

 

We report a grating profile design method based on artificial neural network and the rigorous coupled-wave analysis. By using the learning algorithm of neural network, the desired grating profile could be obtained very quickly. The application could be the fast design for the adaptive gratings or computer generated holography.

 

A fabrication approach using PMMA [poly(methyl methacrylate)] and EGPEA (ethylene glycol phenyl ether acrylate) incorporated with high refractive index species for holographic materials is presented. Diffraction efficiencies with various thicknesses and concentrations are studied.

 

An azobenzene-based material incorporated with polybenzoxazine is fabricated for holographic storage. Performances of diffraction efficiency are evaluated as well.