title: Optical fiber smartphone spectrometer.
abstract: An optical fiber-based smartphone spectrometer incorporating an endoscopic fiber bundle is demonstrated. The endoscope allows transmission of the smartphone camera LED light to a sample, removing complications from varying background illumination. The reflected spectra collected from a surface or interface is dispersed onto the camera CMOS using a reflecting diffraction grating. A spectral resolution as low as δλ∼2.0  nm over a bandwidth of Δλ∼250  nm is obtained using a slit width, ωslit=0.7  mm. The instrument has vast potential in a number of industrial applications including agricultural produce analysis. Spectral analysis of apples shows straightforward measurement of the pigments anthocyanins, carotenoid, and chlorophyll, all of which decrease with increasing storage time.
authors.forename: Md Arafat
authors.initials: MA
authors.lastname: Hossain
authors.forename: John
authors.initials: J
authors.lastname: Canning
authors.forename: Kevin
authors.initials: K
authors.lastname: Cook
authors.forename: Abbas
authors.initials: A
authors.lastname: Jamalipour