Sum regression decomposition of spectral and angle-resolved Mueller matrices from biological reflectors

Abstract

Sum regression decomposition of spectral and angle-resolved Mueller-matrices from biological reflectors, Applied Optics, 2016. 55(15) We show spectroscopic Mueller-matrix data measured at multiple incidence angles of the scarab beetle C. aurata. The Mueller matrix is decomposed by method of regression decomposition and it is shown that this Mueller matrix can be decomposed into a set of two matrices representing one polarizer and one dielectric reflector. We also report on a tentative decomposition of the beetle C. argenteola using the same method.

Graded pitch profile for the helicoidal broadband reflector and left-handed circularly polarizing cuticle of the scarab beetle Chrysina chrysargyrea

“…Focusing probes were used reducing the size of the beam to less than 100 µm. More details on the instrument are found in 23–27,29 . The specular measurements were carried out at angles of incidence ( θ ) (measured from the normal to the surface) from 20 to 75° in steps of 5° in the wavelength ( λ ) range of 245 to 1000 nm.…”

“…However, nature has optimized the cuticle of beetles for multifunctional purposes and broadband reflectors have evolved in several beetles belonging to the Chrysina genus 9–27 . Some Chrysina beetles look silvery because the Bragg band covers a wide spectral range from the ultraviolet to the near infrared.…”

“…argenteola , C . gloriosa ) 21–27 . However, the full capabilities of the Mueller-matrix formalism have not been exploited so far.…”