Study of light emitting modes of InGaP microdisks by using scanning near-field optical microscopy

Using scanning near-field optical microscopy, the photoluminescence of InGaP microdisks with radius about 5 mu m and 10 mu m, respectively, was acquired. Compared with far-field fluorescence images, which show a bright red emission of fluorescence around the circumference of the microdisks, the near-field fluorescent images contain much more details of the mode structure of the light distribution. The main characteristics were found to be whispering-gallery mode from both the near-field and far-field images. As a very rapidly grown new technology, scanning near-field optical microscopy provides us very important information for the study of the light emitting mode of the optical microdisks.