  We achieve direct detection of electron hyperfine shifts in individual
CdTe/ZnTe quantum dots. For the previously inaccessible regime of strong
magnetic fields $B_z\gtrsim0.1$ T, we demonstrate robust polarization of a
few-hundred-particle nuclear spin bath, with optical initialization time of
$\sim$ 1 ms and polarization lifetime exceeding $\sim$ 1 s. Nuclear magnetic
resonance spectroscopy of individual dots reveals strong electron-nuclear
interactions characterized by the Knight fields $|B_e|\gtrsim50$ mT, an order
of magnitude stronger than in III-V semiconductor quantum dots. Our studies
confirm II-VI semiconductor quantum dots as a promising platform for hybrid
electron-nuclear spin quantum registers, combining the excellent optical
properties comparable to III-V dots, and the dilute nuclear spin environment
similar to group-IV semiconductors.
