Terahertz-Wave Generation Based on Optical Frequency Comb and Single Mach-Zehnder Modulator

A novel Terahertz-wave (THz-wave) generation on the strength of optical frequency comb and single push-pull Mach-Zehnder modulator (MZM) with a pair of transmitter and receiver in 0.4-THz band is proposed. The advantages of the optical frequency comb based on phase modulator (PM) 1 and PM2 in series includes the uncomplicated operation and good stability to produce numerous subcarriers at 25-GHz intervals. THz-wave is generated based on two comb lines derived from the same optical frequency comb. One comb line is used as an optical local oscillator (LO) and the other is served as signal carrier for data modulation for heterodyne mixing. We investigate the generation and transmission of a 0.4 THz THz-wave signal carrying 4 Gbaud quadrature-phase-shift-keying (QPSK) or 1 Gbaud 16 quadrature amplitude modulation (16-QAM) data over back-to-back (BTB) transmission or 10 km standard single-mode fiber (SSMF) transmission, with the bit-error-rate (BER) performance below the hard decision forward error correction (HD-FEC) threshold of 3.8e-3.