A Grating-Optic-Less Visible Spectrometer Using Fresnel Zone Plate Patterns on a Digital Light Processor

In this paper, we propose a grating-optic-less single-detector (GOLSD) spectrometer in which both the grating and the focusing optics are integrated in patterns on a digital light processor (DLP), and the commonly used array detector is replaced by a point detector. The pattern on the DLP is set up for each incoming wavelength to focus this component of the spectrum on the detector and prevent the remaining components from reaching it. In this paper, we report the fabrication of the proposed GOLSD for the 550-640 nm wavelength range. The measured full-width at half maximum of the spectrometer is smaller than 4 nm across the above mentioned range. Among other advantages, the introduced spectrometer is low cost and can be easily fabricated for the IR band where one can avoid expensive array detectors.