High precision frequency measurement of terahertz waves using optical combs from a Mach–Zehnder-modulator-based flat comb generator

Abstract

Using a frequency-tunable optical comb generated from a Mach-Zehnder-modulator-based flat comb generator (MZ-FCG) and a nonlinear optical fiber, we demonstrated a frequency measurement of continuous terahertz wave sources with the frequency of 0.1 and 0.6 THz by an electro-optic sampling method. We clearly observed beat signals between the terahertz source and the optical two-tone extracted from the optical comb, allowing us to determine the absolute frequency. Owing to the wide comb spacing of the MZ-FCG, this method has a high potential for the high-speed measurement of the frequency of terahertz wave sources.

20 GHz self‐oscillating parametric optical frequency comb generator using an electroabsorption modulated laser based dual‐loop optoelectronic oscillator

“…Optical frequency combs (OFCs) can be applied in diverse fields including precise measurement [1], arbitrary waveform generation [2], remote sensing [3], high‐speed optical communications [4] and so on [5]. Up to now, the two methods of mode‐locked lasers and external modulation of continuous‐wave (CW) light with radio‐frequency (RF) signal have been frequently used for the generation of OFCs [6, 7].…”