Depth resolution enhancement in optical scanning holography with a dual-wavelength laser source.

In this paper, we use two point sources to analyze the depth resolution of an optical scanning holography (OSH) system with a single-wavelength source. A dual-wavelength source is then employed to improve it, where this dual-wavelength OSH (DW-OSH) system is modeled with a linear system of equations. Object sectioning in DW-OSH is obtained with the Fourier domain conjugate gradient method. Simulation results show that, with the two source wavelengths at 543 nm and 633 nm, a depth resolution at 2.5 μm can be achieved. Furthermore, an OSH system emulator is provided to demonstrate the performance of DW-OSH compared with a conventional OSH system.