  High-flux entangled photon source is the key resource for quantum optical
study and application. Here it is realized in a lithium niobate on isolator
(LNOI) chip, with 2.79*10^11 Hz/mW photon pair rate and 1.53*10^9 Hz/nm/mW
spectral brightness. These data are boosted by over two orders of magnitude
compared to existing technologies. A 130-nm broad bandwidth is engineered for
8-channel multiplexed energy-time entanglement. Harnessed by high-extinction
frequency correlation and Franson interferences up to 99.17% visibility, such
energy-time entanglement multiplexing further enhances high-flux data rate, and
warrants broad applications in quantum information processing on a chip.
