A Si-on-SiC Platform for Interfacing with Vanadium Dopants in the Telecom O-Band

Vanadium color centers in silicon carbide (SiC) offer telecom O-band emission, sub-microsecond optical lifetimes, and second-scale spin relaxation times, rendering them promising candidates for quantum network nodes. However, efficient photon extraction from the high-refractive-index SiC host remains challenging. Here, we introduce a silicon-on-SiC heterogeneous photonic platform in which silicon nanocavities evanescently couple to shallow vanadium dopants in commercial 4H-SiC, enabling efficient zero-phonon line (ZPL) collection under resonant excitation. In as-grown ensembles, we observe Purcell-enhanced photoluminescence with transient spectral hole burning linewidths of 50 MHz on microsecond timescales. In dilute implanted samples, we isolate individual vanadium centers with high-purity single photon emission and a Purcell-enhanced lifetime of 109 ns. The entire optical interface operates through a single lensed fiber, including a 905 nm repump laser that recovers the vanadium charge state with 95% efficiency. These results establish Si-on-SiC as a scalable, foundry-compatible platform for telecom-wavelength spin-photon interfaces.