Mid- to long-wave infrared computational spectroscopy with a graphene metasurface modulator

Vivek Raj Shrestha; Benjamin Craig; Jiajun Meng; James Bullock; Ali Javey; Kenneth B Crozier

doi:10.1038/s41598-020-61998-w

Mid- to long-wave infrared computational spectroscopy with a graphene metasurface modulator

Sci Rep. 2020 Mar 25;10(1):5377. doi: 10.1038/s41598-020-61998-w.

Authors

Vivek Raj Shrestha¹, Benjamin Craig¹, Jiajun Meng², James Bullock², Ali Javey^{3

4}, Kenneth B Crozier^{5

6

7}

Affiliations

¹ School of Physics, University of Melbourne, VIC, 3010, Australia.
² Department of Electrical and Electronic Engineering, University of Melbourne, VIC, 3010, Australia.
³ Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA, 94720, USA.
⁴ Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
⁵ School of Physics, University of Melbourne, VIC, 3010, Australia. kenneth.crozier@unimelb.edu.au.
⁶ Department of Electrical and Electronic Engineering, University of Melbourne, VIC, 3010, Australia. kenneth.crozier@unimelb.edu.au.
⁷ Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems, University of Melbourne, Victoria, 3010, Australia. kenneth.crozier@unimelb.edu.au.

Abstract

In recent years there has been much interest concerning the development of modulators in the mid- to long-wave infrared, based on emerging materials such as graphene. These have been frequently pursued for optical communications, though also for other specialized applications such as infrared scene projectors. Here we investigate a new application for graphene modulators in the mid- to long-wave infrared. We demonstrate, for the first time, computational spectroscopy in the mid- to long-wave infrared using a graphene-based metasurface modulator. Furthermore, our metasurface device operates at low gate voltage. To demonstrate computational spectroscopy, we provide our algorithm with the measured reflection spectra of the modulator at different gate voltages. We also provide it with the measured reflected light power as a function of the gate voltage. The algorithm then estimates the input spectrum. We show that the reconstructed spectrum is in good agreement with that measured directly by a Fourier transform infrared spectrometer, with a normalized mean-absolute-error (NMAE) of 0.021.