The phase range extension and accuracy improvement in Fresnel biprism-based digital holography microscopy.

We report a highly stable and affordable dual-wavelength digital holographic microscopy system based on common-path geometry. A Fresnel biprism is used to create an off-axis geometry, and two diode laser sources with different wavelengths λ1 = 532 nm and λ2 = 650 nm generate the dual-wavelength compound hologram. In order to extend the measurement range, the phase distribution is obtained using a synthetic wavelength Λ1 = 2930.