Biphoton frequency comb group

Time-frequency quantum information enhances quantum communication and computing by boosting information capacity. We use a single setup combining Hong-Ou-Mandel (HOM) and Franson interference to generate and verify a tunable biphoton frequency comb (BFC) with 5, 7, and 9 modes. Two-photon interference achieves 98% visibility, surpassing the classical limit and confirming strong quantum entanglement. This efficient and flexible method is promising for high-dimensional quantum networks and information processing.