Fig. 4From: InAs/GaAs Quantum Dot Dual-Mode Distributed Feedback Laser Towards Large Tuning Range Continuous-Wave Terahertz ApplicationThe spectrum of the dual-mode LC-DFB laser. a Emission spectra of the dual-wavelength LC-DFB laser with a different grating period. b Wide spacing of dual-mode lasing spectra of the LC-DFB laser with an ultra-short cavity length of 450 μmBack to article page