Fig. 3: Experimental setup and characterization of the EO comb.
From: High-precision time-domain stereoscopic imaging with a femtosecond electro-optic comb
a Experimental setup. Col., collimator; EDFA, erbium-doped fiber amplifier; HWP, Half-wave plate; M1-6, mirrors; 50/50, fiber coupler. The focus length for lenses L1 and L3 is 100 mm, and for L2 and L4 is 75 mm. The dashed box shows a 90 MHz sine wave being converted into a train of ultrashort pulses by an EO comb. b Linearly sweeping the comb’s repetition frequency (fr) from 90 to 300 MHz within 210 ms. Inset: RF spectra obtained by short-time Fourier transform, showing instantaneous frequencies of the RF synthesizer and the EO comb. c Autocorrelation traces of the EO comb versus modulation frequencies (fm). The data is measured after the detection collimator, and the frequency deviation is fixed at 250 kHz. d Fractional stability of the EO comb and the RF synthesizer. The comb stability deteriorates after 200 s due to the use of fibers. e, f High-resolution and large field-of-view images of the resolution target (1951-USAF) recorded by one of the cameras. The central patterns in (e, f) correspond to groups 6 and 0, respectively.
