Using Temperature to Reduce Noise in Quantum Frequency Conversion
Paulina S. Kuo, Jason S. Pelc, Carsten Langrock, M. M. Fejer
Quantum frequency conversion (QFC) is important in quantum networks to interface nodes operating at different wavelengths and to enable long-distance quantum communication using telecommunications wavelengths. Unfortunately, frequency conversion in actual devices is not a noise-free process. One main source of noise is spontaneous Raman scattering, which can be reduced by lowering the device operating temperature. We explore frequency conversion of 1554-nm photons to 837 nm using a 1813-nm pump in a periodically poled lithium niobate waveguide device. By reducing the temperature from 85 C to 40 C, we show dark count rates can be reduced significantly, which is in good agreement with theory.