What we can do further in manipulating or controlling biphoton source?
A biphoton source presents one of the ideal composite quantum systems to possess quantum entanglement. In addition to this resource of entanglement, useful for the purpose of entanglement distribution or quantum state teleportation, a biphoton source can be flexible and scalable due to its multiple facets of degrees of freedom. They can be polarizations, frequency-bin qubits, OAM (orbital angular momentum), and continuous frequency modes. Furthermore, photons are great carriers of information and they can work with atoms, ions, or solid-state qubits to potentially realize a quantum computer if not entirely impossible in another 100 years. Photons are particularly fascinated to me, especially they do not have wavefunctions. In the Bible, "And God said, Let there be light: and there was light." This intriguing object might hold the clue of bizarre origin of universe/unsettled theory of quantum gravity, along with theorized Hawking radiation.