Miniature Spectrometer Based on Gold Nanorod-Polyvinylpyrrolidone Film

Abstract

Miniaturization of spectrometers is crucial for the application of spectroscopic analysis in many fields. As a new paradigm of miniature spectrometers, reconstructive spectrometers have attracted extensive attention due to their ultracompact design. However, methods with simple, low-cost, and flexible manufacturing processes are still urgently needed to enable wide applications of this technique. Here, we propose a miniature spectrometer based on gold nanorod-polyvinylpyrrolidone (AuNR-PVP) film. By employing a photochemical reshaping technique, spectral transmittances at different areas of the film can be simply defined and patterned during a single exposure. Therefore, the spectral elements can be fabricated and customized through a convenient and inexpensive approach, and a sophisticated design is not necessary. We show that incident spectra can be reconstructed from image signals generated by a CMOS image sensor, of which the spectral responses are spatially modulated by integrating with a AuNR-PVP-based gradient filter. Experiment results demonstrate that the spectrometer performs well in the reconstruction of both narrowband and broadband spectra.