Characterisation of optical properties in micro-patterned InGaN quantum wells

Optical resonance modes of micro-scale patterned InGaN quantum wells includ ing disks and rings of various diameters (0.5-20 mum) have been investigate d. For the observation of resonant modes, well-defined features and striati on-free sidewalls were essential. Each of the patterned structures displaye d resonant modes superimposed on the main InGaN photoluminescence peak. The large number of such modes observed has allowed analysis of the mode spaci ng as a function of both wavelength and diameter. Comparison with a simple model has confirmed that these are "whispering gallery" modes. No evidence of radial modes was observed. Microrings showed fewer optical resonance mod es than microdisks. In addition, the number of observable modes correlated with the width of microring structures.