Tunable and angle-independent thermal emitter based on surface phonon polariton mode in the mid-infrared range

A tunable and angle-independent thermal emitter which consists of silicon carbide (SiC) gratings incorporated with Ge2Sb2Te5 (GST) phase change materials (PCMs) in the mid-infrared (MIR) range has been proposed and investigated. The reflectivity under different conditions is simulated by the rigorous coupled wave analysis (RCWA) method. It is shown that a large shift of reflection dip is attainable within the Reststrahlen band of SiC (10.288 μm-12.563 μm) for transverse magnetic (TM) polarization light, when GST is changed between the crystalline and amorphous states. The deep reflection dips appeared for the two states of GST are attributed to the excitation of surface phonon plaritions (SPhPs). In addition, the incident angle independence of wavelength for both states of GST is obtained, which is a major feature of the tunable thermal emitter.