Reconstruction of Double-Exposed Terahertz Hologram of Non-isolated Object

When the non-isolated imaging objects are complex or critical imaging precision is required, single-exposure digital hologram technique may be insufficient. So in this paper, double-exposure method is adopted in 2.52-THz inline digital holography simulations and experiments. Experimental results indicate that, compared with the results reconstructed by single-exposure amplitude-constrained phase retrieval algorithm (S-APRA), double-exposure phase-constrained phase retrieval algorithm (D-PPRA) increases the contrast of the reconstruction image by 0.146 and double-exposure amplitude-constrained phase retrieval algorithm (D-APRA) increases the contrast by 0.225. In addition, when applied to non-isolated object reconstruction, phase retrieval algorithms with only amplitude constraint on the object plane work better than those with both amplitude and phase constraints.