Fig. 1. (a) Experimental setup of the high-resolution MIR dual electro-optic comb interferometer. AWG: arbitrary waveform generator; MZM: Mach-Zehnder modulator; DFB: distributed feedback laser; SG: signal generator; AOM: acoustic optical modulator; AFG: arbitrary function generator; DD-MZM: dual-drive Mach-Zehnder modulator; MPD: mid-infrared photodetector. (b) Experimental setup of the DFG system. Col: collimator; EDFA: erbium-doped fiber amplifier; YDFA: ytterbium-doped fiber amplifier; HWP: half-wavelength plate; DM: dichroic mirror; LPF: long-pass filter.

Fig. 2. (a) Output spectrum of the MZM operating at a bias voltage setting that enhances even-order sidebands. (b) Spectrum after lock-amplifying the second-order sideband utilizing the injection locking effect.

Fig. 3. (a) Experimental setup to select the positive second-order sideband by optical tunable filter. (b) Experimental setup to select the positive second-order sideband by injection locking. (c) Spectrum after filtering with the OTF. (d) Spectrum of the locked and amplified positive second-order sideband.

Fig. 4. (a) Spectrum of EOFC generated by DD-MZM at 1550 nm. (b) Spectrum of EOFC based on spectral interleaving at 1550 nm.

Fig. 5. (a) Demodulated spectrum of MIR DCI with a line spacing of 100 MHz at 3.3 µm. (b) Zoomed-in figure of (a) around 90.8 THz.