Fresnel incoherent correlation holography with phase-shifting technology

The Fresnel Incoherent Correlation Holography (FINCH) technology is an on-axis system, which needs phase-shifting technology to eliminate the conjugate image and the zero-order image. Based on the theory of FINCH imaging system, the formula of n-step phase-shifting method was derived, an experimental light path of incoherent light reflection digital holographic recording was constructed. The effect of n-step phase-shifting on the FINCH imaging system through simulation and experiment was studied. The results show that the quality of the reconstructed image cannot significantly improved by increasing phase-shifting steps; two-step phase-shifting can enhance recording speed, whose zero-order image can be suppressed by eliminating original image and wavelet decomposition. A comparison was made between the reconstructed images obtained separately by averaging hologram and hologram photographing once of three-step phase-shifting, and the result shows that the quality of the reconstructed image is getting better and better with the increase of the shots. Not only the background noise is greatly weakened, but also the intensity of the pixels becomes stronger and stronger, which provides a new way and new experimental basis to promote the development of the FINCH system.