  This work investigates a kind of metallic magnetic cavity based on slit-hole
resonators (SHRs). Two orthogonal hybrid magnetic resonance modes of the cavity
with a large spatial overlap are predesigned at the wavelengths of 980 nm and
1550 nm. The Yb-Er co-doped material serving as a gain medium is set in the
cavity; this enables the resonator to have high optical activity. The numerical
result shows that the strong lasing at 1550 nm may be achieved when the cavity
array is pumped at 980 nm. This double resonance nanolaser array has potential
applications in future optical devices and quantum information techniques.
