Single-shot multiwavelength phase unwrapping using a single reference beam and a monochromatic image sensor

We propose single-shot multiwavelength phase unwrapping using a single reference beam and a monochromatic image sensor. A single beam containing multiple wavelengths passes through a reference arm and acts as reference waves. Multiple-wavelength information is multiplexed in the space domain on the monochromatic image sensor and is separated in the spatial frequency domain by utilizing the spatial frequency difference of interference fringes at multiple wavelengths. From a single hologram, multiwavelength phase unwrapping is conducted and an unwrapped phase image is obtained. Both transmission and reflective single-shot multiwavelength digital holography systems using a monochromatic image sensor can be constructed with a simple optical setup employing the proposed technique. Single-shot multiwavelength phase unwrapping by the proposed technique is numerically simulated and experimentally demonstrated.