Telecommunications-band heralded single photons from a silicon nanophotonic chip
Click to view
Photon pair production. (a) Scanning electron microscope image of the 35-ring CROW used in this work. (b) Experimental setup used to measure correlated photon pairs generated by the CROW. The 1520 nm to 1630 nm tunable laser is used for classical FWM experiments to identify the signal and idler wavelengths, but is disconnected during SFWM/photon pair generation measurements. EDFA = erbium-doped fiber amplifier, WDM = wavelength division multiplexer, FPC = fiber polarization controller, VOA = variable optical attenuator, OSA = optical spectrum analyzer, SPAD = single photon avalanche diode. (c) FWM spectrum in which a 1549.6 nm pump adds stimulated photons into the 1570.5 nm probe and generates a new field at 1529.5 nm. The spectral peaks in between the pump and signal/idler fields are due to transmission of (unfiltered) EDFA amplified spontaneous emission (ASE) through the CROW passbands. In photon pair measurements, this ASE is suppressed by >150 dB by the pump isolation WDMs. (d) CAR as a function of power at theCROW input, for continuous wave pumping.29 (e) Number of coincidences (red) and accidentals (blue) at the CROW output as a function of power at the CROW input. Results are plotted in units of (left y-axis) counts per gate and (right y-axis) counts per second.30
Click to view
Heralded single photon measurement. (a) Schematic of the experimental setup used to perform heralded single photon measurements. The Si CROW is pumped by a pulsed 1549.6 nm laser (2.5 ns pulses, 8 MHz repetition rate) generated by a modulated and amplified diode laser. Generated photon pairs are spectrally isolated and separated into the C-band (1529.5 nm) and L-band (1570.5 nm). Detection of an L-band photon by an InGaAs/InP SPAD is used to trigger a Hanbury-Brown and Twiss photon correlation measurement on the C-band photon. (b) Heralded as a function of average power at the CROW input.31 (c) Heralding rate at the CROW output as a function of average power at the CROW input. Results are plotted in units of (left y-axis) heralding photons per second and (right y-axis) heralding photons per pulse.
Article metrics loading...
Full text loading...