Silicon nitride core rib waveguides and methods of manufacturing the same

A quantum memory system comprising an optical device comprising a silicon nitride core on a rare-earth doped polycrystalline ceramic substrate, a magnetic field generation unit, a storage photon generator, and one or more pump lasers, wherein:

• the optical device is positioned within a magnetic field of the magnetic field generation unit when the magnetic field generation unit generates the magnetic field;
• the one or more pump lasers are optically coupled to the optical device;
• the storage photon generator is optically coupled to the optical device and is structurally configured to output an entangled pair of storage photons comprising a first entangled storage photon entangled with a second entangled storage photon;
• and
• the optical device further comprises a cladding surrounding the silicon nitride core.