Photo-acoustic spectroscopy toward spatial mapping of chirality [Invited]

Chirality, the absence of mirror symmetry, defines matter interactions and properties at all scales, with significant implications in fields spanning nanotechnology, pharmaceuticals, and agrochemicals. Circular dichroism (CD), the differential absorption of circularly polarized light of different handedness in chiral media, characterizes chirality. Here, we apply a photo-acoustic spectroscopy (PAS) as a scattering-free method for characterizing absorption and CD. We investigate asymmetric silver-based metasurface in a broad spectral range; we show CD dependence on the incident angle and modulation frequency. We then use optimal wavelength-angle points to perform spatial mapping of CD, which shows perspective in surface CD and uniformity characterization.