Spectroscopy system using digital camera as two dimensional detectors for undergraduate student laboratory

Abstract

In this paper, we propose spectroscopy system, which use Complementary metal–oxide–semiconductor (CMOS) image sensor as two dimensional detectors, for studying in undergraduate laboratory. The goal of this system is to make students understand internal structure of commercial spectrometer and characteristic of light spectrum. Light with various wavelengths propagated via variable slit, which is used to adjust width of spectrum, has been focus on reflective grating and then separated to various spectrum. After that, separated spectrum has been recorded by CMOS image sensor which consists of two dimensional array pixels. Each pixel can be determined as wavelength of light by calibrating with Mercury lamp which is standard light source that has exact spectrum value. Measuring factor i.e. sensitivity and spectral resolution have been considered. By using CMOS image sensor, student can observe distribution of real light spectrum and spectrum graph together. The results show that characteristic spectrum of Mercury lamp obtained from our system exact with standard value. By considering measuring factor of spectrometer, small slit width influence system gain high resolution but it cause system has low sensitivity. Spectrum of Mercury lamp, Hydrogen lamp, Argon lamp, led flash of smartphone, and compact fluorescent lamp have been shown and compared. Moreover, our system not only be applied for undergraduate studying, but also might be applied with other optical spectroscopy method in future. © 2017 Elsevier Ltd. All rights reserved.