Quantum advantage of fully guided single-mode squeezing for quantum teleportation and sensing

In this Letter, we demonstrate an operational analysis of fully guided single-mode squeezing in the telecom C-band, highlighting its entanglement potential and sensing performance under realistic purity constraints. We observe -1.81±0.05 dB of squeezing at 1550 nm, equating to -4.11±0.05 dB of generated squeezing (after accounting for losses) using a Zn-indiffused MgO-doped periodically-poled lithium niobate (MgO:ppLN) ridge waveguide. To demonstrate the practicality of this fully-guided squeezer, we employ experimentally measured quadrature variances to compute performance metrics such as purity, entropy, and quantum Fisher information for phase sensitivity estimation to demonstrate ∼11% quantum advantage over coherent states through quantum Cramer-Rao bound. We further quantify the entanglement potential of the single-mode squeezed vacuum and establish the nonclassicality of the corresponding two-mode squeezed states using Duan's inseparability criterion. The source also shows potential for continuous-variable quantum teleportation, with a computed fidelity of ∼73.4%. These results establish practical benchmarks for fiber-compatible squeezed-light sources in telecom-band continuous-variable quantum applications.