New approach to extract phase feature of 3-D objects by wavelength-scanning digital holography

A new approach to extract phase feature of 3-D objects based on wavelength-scanning digital holography and numerical reconstruction technique is proposed in this paper.A number of holograms are recorded on a digital camera and reconstructed numerically by a computer with different wavelengths spaced at regular intervals.The theoretical analysis and computer simulations demonstrate that those pixels with the same phase of a 3-D object can focus on the same reconstruction plane.And those pixels with different phase of a 3-D object focus on the different reconstruction planes.Therefore the phase information of a 3-D object can be described by a series of reconstructed images on different planes.