Panasonic Color Splitting Array paper appears in open access on
Readcube. The figure below explains the color splitting principle (click on image to enlarge):
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Figure 1: Operational principle of a symmetric deflector. a, The symmetric deflector has a plate-like structure and is composed of a transparent medium that has a higher refractive index than the surrounding material. When light enters a symmetric deflector of width w and length l, a phase difference δ develops between the light propagated through the deflector and the light propagated through the surrounding volume. If δ is an even multiple of Ï€, the transmitted light is undeflected (arrow U), and if δ is an odd multiple of Ï€, the transmitted light is deflected at equal ± angles (arrows +D and −D). The phase difference δ rises and falls as a function of wavelength λ, so the ratio between the amount of undeflected light and the amount of ± deflected light varies depending on λ. b, Plot of the cross-sectional refractive index distribution for a symmetric deflector. Shape and position of the deflector: w = 0.28 µm, l = 1.20 µm, d = 2.00 µm. Refractive indices of the deflector medium (SiN) and the surrounding medium (SiO2): n = 2.03 and 1.46. c,d, Plots of cross-sectional light intensity distribution for a symmetric deflector with λ = 430 nm (c) and λ = 600 nm (d). The Gaussian beam has a waist diameter D (full width at 1/e2 maximum) of 1.43 µm. As the wavelength increases, deflected light becomes undeflected. e,f, Plots of light intensity distribution at the detector surface for a symmetric deflector for λ = 430 nm (e) and λ = 600 nm (f). Three 1.43 µm × 1.43 µm detectors (R, C and L) are placed next to one another on the detecting surface. As the wavelength increases, the spots on the detector move towards the centre. |
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