Heralded single photons (HSPs) generated by spontaneous parametric down-conversion (SPDC) are useful resource to achieve various photonic quantum information processing. Given a large-scale experiment which needs multiple HSPs, increasing the generation rate with suppressing higher-order pair creation is desirable. One of the promising ways is to use a pump laser with higher repetition rate. However, little is known of the influence of the pump repetition rate on the indistinguishability of the HSP. In this work, we reveal that, as the pump repetition rate gets higher, the spectral purity of the HSP is degraded due to the sparse comb structure of the pump pulse. Furthermore, we show that the above difficulty is circumvented by performing temporal filtering. As a proof-of-principle experiment, we experimentally demonstrate a high-visibility Hong-Ou-Mandel interference between two independent HSPs generated by SPDC with 3.2 GHz-repetition-rate mode-locked pump pulses via temporal filtering. Our method forms an important building block to achieve large-scale, high-fidelity, and high-speed photonic quantum information processing.
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