Nano Lett. Article ASAP https://doi.org/10.1021/acs.nanolett.8b03937 (2018)
Many quantum optics applications require integrated photonic circuits that generate, process and detect single photons with high control: hence the desire for deterministic, non-intrusive manipulation of the optical properties of components such as single-photon emitters, beam splitters or couplers. Elshaari et al. now combine bottom-up and top-down techniques to develop a single-photon source and frequency filter on the same platform, both with voltage-controlled frequency tuning.
A piezoelectric substrate sandwiched between two electrodes controls the emission frequency of a single-photon emitter and the pass frequency of a ring resonator by means of strain. They pattern a SiN waveguide on a piezoelectric substrate and place an InAsP/InP nanowire quantum dot at its end by nanomanipulation. A potential difference applied to the piezoelectric layer then stretches the nanowire. The emission frequency shifts linearly and reversibly with the applied voltage and shows frequency stability over hours. Elshaari et al. also pattern a ring resonator on the same type of substrate, which can be used as a pass filter. Strain applied by the piezoelectric substrate changes its transmission frequency, again linearly with voltage. Their approach avoids wire bonding but uses direct patterning onto the piezoelectric substrate, which increases the wavelength stability and precision of the device.