Geneation of Coherent Terahertz Carriers in the 3 THz Range Using Optical-Comb-Based THz Source for Terahertz Communications

Abstract

We proposed a terahertz (THz) communication system operating in the 3 THz range using an optical-comb-based THz source and a heterodyne receiver system using a hot electron bolometer mixer (HEBM) along with a quantum cascade laser (QCL) operating at 3 THz for a local oscillator. The THz source is composed of a Mach-Zehnder-modulator-based flat comb generator (MZ-FCG), and a uni-traveling-carrier photodiode (UTC-PD). By using a phase-locked loop (PLL) system, the oscillation frequency of the QCL was highly stabilized. By using this system, generation and detection of coherent THz carriers in the 3 THz range have been demonstrated, which had a phase noise of -70 dBc/Hz at an offset frequency of 100 kHz.