Fig. 1. Side-view SEM images of microdisks with the diameters of (a) 3.3 μm, (b) 8 μm, and (c) 18 μm.

Fig. 2. Photoluminescence spectra of the microdisks with the diameters of (a) 3.3 μm, (c) 8 μm and (e) 18 μm with the increase of pump power at room temperature. Integrated PL intensity versus pump power for (b) 3.3 μm microdisk, (d) 8 μm microdisk and (f) 18 μm microdisk.

Fig. 3. Radial electric field profiles (|E|²) of (a) 3.3 μm microdisk at 444 nm, (b) 8 μm microdisk at 440 nm and (c) 18 μm microdisk at 446 nm.

Fig. 4. Axial electric field profiles (|E|²) of (a) 3.3 μm microdisk, (b) 8 μm microdisk, and (c) 18 μm microdisk with vertical sidawalls.

Fig. 5. Axial electric field profiles (|E|²) of (a) 3.3 μm microdisk, (b) 8 μm microdisk, and (c)18 μm microdisk with inclination angles of 2.5°. Axial electric field profiles (|E|²) of (d) 3.3 μm microdisk, (e) 8 μm microdisk, and (f) 18 μm microdisk with inclination angles of 5°.