LATERAL-mode-beating for Terahertz excitation in 1.5-µM DBR laser

We report a Terahertz (THz) excitation source based on a dual-lateral-mode ridge-waveguide Distributed Bragg Reflector laser (DBR) with an optimized 4 µm ridge width in the 1.5-µm range. Dual-lateral-mode generation and beating are verified experimentally. In the experiments, Terahertz signals of 1.133 THz, 1.134 THz, 1.235 THz and 1.24 THz are obtained under different bias conditions. The two wavelengths can be tuned continuously with small strength difference (< 5 dB) and high side-mode suppression ratio ( SMSR > 45 dB).