Continuous Tunable Terahertz Wave Generation via a Novel CW Optical Beat Laser Source

摘要

A novel technique of generating two colors or dual-wavelength in a fiber hybrid compound-ring resonator is discussed. Generation of continuous-wave terahertz radiation is demonstrated by using a dual-wavelength widely tunable C-band SOA-based fiber compound-ring laser as a light source, which excites a continuous-wave terahertz photomixer operating at 1.55 μm telecom optical wavelengths. The proposed dual-wavelength fiber laser has a hybrid compound-ring resonator structure and external reflectors that allow output power upscaling and single or dual-output port operation, respectively. Wavelength selection and continuous tunability are achieved by a widely tunable optical filter sandwiched between two fiber-Bragg grating filters of similar Bragg center wavelength. The difference wavelength tuning range of 20.42 nm (i.e., 2.51 THz) is demonstrated in the C-band. Continuous-wave terahertz radiation with continuous tunability between 0.8 and 2.51 THz at room temperature using only a fiber laser source is achieved via photomixing.