Figure 5 : Far-field characterization.

From: Photonic quasi-crystal terahertz lasers

Figure 5

(a) 3D simulation of the out-of-plane emission of the main optical P-mode of Fig. 1c and Fig. 3, derived by applying the Stratton–Chu method to its near-field emission. (b,c) Far-field emission patterns of two devices obtained by scanning a pyroelectric detector at a distance of about (b) 8 cm and (c) 16 cm from the device surface. (b) Far-field measured from the device with a=21 μm and R=0.26. (See Fig. 2f for the emission spectrum of this device.) Similar results have been found for other devices showing P-mode emission (a=23 μm, r/a=0.33 and r/a=0.31 in Fig. 2b; a=22 μm, r/a=0.31 and r/a=0.28 in Fig. 2d). (c) Far-field measured from the device with a=21 μm and r/a=0.33. (See Fig. 2f for the emission spectrum of this device) Similar results have been found for other devices (a=22 μm, r/a=0.26 in Fig. 2d; a=21 μm, r/a=0.31 in Fig. 2f).