Which smartphone for a smartphone-based spectrometer?

Authors:

• Emil Pituła,
• Marcin Koba,
• Mateusz Jakub Śmietana

Abstract

In this work we discuss an application of over 60 various smartphone devices currently available on the market as low-cost spectrometers. To analyze and compare the smartphones, they were supplemented by a universal 3D-printed adapter containing mainly a diffraction grating and a multimode optical fiber projecting light from a smartphone’s light source onto the diffraction grating. The diffraction pattern is then casted on the smartphone’s camera. Acquired images were further converted to spectral patterns and compared. Modifications made to the images by the smartphones on both hardware and software sides were also analyzed. The aim of this work was to identify influence of the devices’ components (hardware) and settings (software) on the obtained spectrum. Finally, we analyzed optical fiber sensors based on the lossy-mode resonance effect, using commercial and selected smartphone-based spectrometers. The results for refractive index sensing were discussed indicating limitations of the smartphone-based solution.