Multiwavelength off-axis digital holography with an angle of more than 40 degrees and no beam combiner to generate interference light.

Abstract

We propose single-shot multiwavelength digital holography with an extremely large incident angle and show the digital recording of multiple object waves at multiple wavelengths with an angle of more than 40 degrees and no beam combiner to generate interference light. Both the avoidance of the crosstalk between the object waves at different wavelengths and the space-bandwidth extension are simultaneously achieved with a single-shot exposure of a monochromatic image sensor and a reference beam even when the wavelength difference between the object waves is small. An extremely large angle can be set by utilizing the signal theory. An angle of up to 40.6 degrees was introduced, interference fringes with an 818 nm period at the wavelength of 532 nm were generated, and an image sensor recorded a two-wavelength-multiplexed hologram. Resolution improvement was experimentally demonstrated using two-wavelength digital holography with the wavelengths of 640 and 532 nm.