Phase-Shifting Digital Holographic Microscopy In Reflection Configuration

Digital Holographic Microscopy (DHM), as an important application inmicro-structure detection, achieve the3D reconstruction and measurement bychanging the height, amplitude transmittance of object wave into reconstructedintensity and phase. Compared with some high accuracy devices, Digital HolographicMicroscopy is of great advantages such as full field, quantitative detection,non-invasion, and so on, besides, its simple structure even make it a lower cost andtime consumption, which make the mass producing be realizable, because of this,more and more attentions are paid in this field. Phase-shifting digital holographicmicroscopy, which can reconstruct the holograms efficiently, is widely applied inmany fields. However, the researches of phase-shifting digital holographicmicroscopy in reflection configuration isn’t found so much, the research on this is ofgreat importance and a bright future. In this paper, the research is focused onphase-shifting digital holographic microscopy in reflection configuration, theexistence problems in digital holographic microscopy are demonstrated both in theoryand experiment. Four efforts are involved:1. The holography, especially the digital holography is introduced, the developmentof the holography is summarized, the research progress domestic and overseas ondigital holographic microscopy is summarized and the future of the digitalholographic microscopy is put forward.2. The principle of the holography, especially the digital holography is demonstratedin theory; the principle of the phase-shifting theory is demonstrated in detail; thephase unwrapping theory is introduced; and, the frequency domain filteringtechnology is summarized; finally, the reconstruction algorithms are written byusing MatLab software.3. An improved Linnik interferometer for phase-shifting digital holographicmicroscopy in reflection configuration is demonstrated; some phase-shiftingconfigurations are analyzed and compared. Higher phase-shifting precision is achieved in this improved Linnik interferometer. For the dip angle existing inobject wave, the elimination is achieved based on Fourier-transform fringe phasedemodulation theory.4. For the reconstruction errors resulting from the environment vibration,phase-shifting and so on, an improved phase-shifting algorithm is demonstratedbased on Fourier-transform fringe phase demodulation theory, higher precisionshifted phase is achieved and the object wave is clearly reconstructed.