(A) Spectrum of the active
cladding microring laser with R = 25 μm, showing
radial modes (magenta triangle),
WGMs (blue dot). (B) Schematic of the coexistence of radial modes
and WGMs. (C)–(J) Simulation results on active cladding microring,
where (C)–(F) for pure ring: (C) dependence of reflectivity
on wavelength, (D) intensity distribution of the light source formed
by the active layer in the xy-plane at 572.25 nm,
(E) intensity distribution of fundamental radial mode at 572.51 nm,
and (F) intensity distribution of WGM at 602.25 nm. And (G)–(J)
for grating integrated ring: (G) dependence of reflectivity on wavelength,
(H) intensity distribution of the light source formed by the active
layer in the xy-plane at 587.92 nm, (I) intensity
distribution of fundamental radial mode at 587.79 nm, and (J) intensity
distribution of WGM at 602.24 nm.