Reflectance of color standards and laser lines

Reconstructed color Image

HERA was employed to image a white and four colored (green, blue, red, yellow) calibrated diffusive reflectance spectral standards, illuminated by a broadband Xenon lamp. In addition, a green (λ = 532 nm) and a red (λ =635 nm) diode lasers were added to the scene.

Spectra at selected pixels in the image are shown on the right. In the top panel, the two narrow lines correspond to the laser diode spectra, demonstrating very high spectral resolution (3THz, i.e. ~4 nm at λ = 635 nm) and dynamic range (the background level is 30dB lower than the peak, see inset). In the lower panel, the dashed lines are the certified reflectivity values of the four coloured standards, while the solid lines are the spectra retrieved by HERA, with excellent spectral accuracy in the visible and near-infrared spectral range (400-1000 nm).

Read more here:

A. Perri et al., “Hyperspectral imaging with a TWINS birefringent interferometer“, Optics Express 27, 15956-15967 (2019)