Fermi level tunableness of graphene for nonreciprocal emitter with magneto-optical material InAs

Nonreciprocal thermal radiation is a developing area of research that involves integrating anisotropic magneto-optical materials into optical systems. Most current investigations concentrate on the phenomenon of nonreciprocal thermal radiation within the transverse magnetic (TM) polarization framework. In this study, we present a dual-function nonreciprocal emitter that operates under transverse electric (TE) polarization. Within the wavelength range of 15–15.5 μm, we observe two guided mode resonances (GMRs) under TE polarization, while a single GMR is noted under TM polarization, effectively achieving dual-function nonreciprocal emission. The emitter utilizes metallic aluminum (Al) alongside the magneto-optical material indium arsenide (InAs), demonstrating over 90% nonreciprocity at certain incident wavelengths with an external magnetic field of 4 T. Additionally, a graphene layer is incorporated on the grating ridge to accommodate potential peak position shifts due to manufacturing variances. This research offers significant prospects in the domain of asymmetric thermal radiation and seeks to enhance energy conversion efficiency.