Fig. 2: Experimental set-up. | Light: Science & Applications

Fig. 2: Experimental set-up.

From: Spectral control of nonclassical light pulses using an integrated thin-film lithium niobate modulator

Fig. 2

Orthogonally polarized photon pairs were generated by pumping a type-II phase-matched periodically poled potassium titanyl phosphate (PPKTP) crystal with a mode-locked Ti:sapphire laser. After being separated by a fiber polarization beam splitter (PBS), the signal photons (horizontally polarized, H) went through a double-pass TFLN modulator (EOM) with Vπ as low as 2.3–2.8 V in 10–40 GHz range. The output either passed through a 20 km fiber (labeled Dispersion) followed by superconducting nanowire single-photon detectors (SNSPDs) for dispersion-based spectrum measurement or a 50:50 beam splitter (BS) for quantum interference with the idler photon (vertically polarized, V), which passed through a polarization controller (PC) and a tunable delay. The RF drive of the modulator was phase-locked to the pump laser with a tunable phase delay. Waveshapers (WS) were used to apply spectral filtering or spectral phase; LPF long-pass filter, BFP bandpass filter, PLO phase-locked oscillator

Back to article page