Fig. 1: Scheme and principle of the proposed electrochromic computational on-chip spectrometer (ECOS).
From: Miniaturized on-chip spectrometer enabled by electrochromic modulation
a Schematic of ECOS, which consists of an electrochromic filter array on top of the CMOS sensor. The electrochromic filter array consists of an ECD embedded in two polarizers with different polarization angles. The ECD consists of five layers of ITO/WO3/electrolyte/NiOx/ITO on a mica substrate. b Principle of ECOS. The transmission spectra of different electrochromic filter units at different voltages (‘0 V’, ‘−1.2 V’, and ‘−1.5 V’). \(S(\lambda )\) refers to the unknown light for testing. c The reconstructed spectra at different voltages. The m denotes different detection modes: ‘m = 1 (blue)’ refers to the mode of using only ‘0 V’, ‘m = 2 (green)’ refers to the mode of using ‘0 V’ and ‘−1.2 V’, and ‘m = 3 (red)’ refers to the mode of using ‘0 V’, ‘−1.2 V’, and ‘−1.5 V’
