  We show that Purcell effect can lead to a substantial enhancement in the
maximum cooling power for solid-state laser cooling. We numerically demonstrate
such enhancement in a patterned slot-waveguide structure using ytterbium-doped
silica as the active material. The enhancement arises primarily from the
increase of saturation power density and the escape efficiency, and can persist
in spite of the presence of parasitic absorption in the structure surrounding
the active material. Our results point to a new opportunity in photonic
structure design for optical refrigeration.
