Laplace Operation-Based DC Noise Reduction in Digital Holography

The in-line holography has obvious advantages especially in wider spatial bandwidth over the off-axis holography. However, a direct current (DC)-noise and an unwanted twin image should be separated or eliminated for a high quality reconstruction. Therefore, we introduce an effective Laplace operation-based numerical approach for DC-noise reduction in the in-line holography. The DC-noise in a holographic fringe pattern can be efficiently reduced by applying a second derivative operation while maintaining the two real and twin terms. For the performance evaluation, the proposed method is compared with the existing approaches, including the intensity average subtraction and frequency-domain filtering, which are generally used for the numerical holographic reconstruction. Experimental results show that the proposed method is numerically appropriate, and provides the high quality reconstruction for a digital holography. Therefore, we believe that the proposed scheme can be a useful tool for high quality reconstruction in the in-line holography.