  Nanolasers have great potential as both on-chip light sources and optical
barcoding particles. We demonstrate ultrasmall InGaP and InGaAsP disk lasers
with diameters down to 360 nm (198 nm in height) in the red spectral range.
Optically pumped, room-temperature, single-mode lasing was achieved from both
disk-on-pillar and isolated particles. When isolated disks were placed on gold,
plasmon polariton lasing was obtained with Purcell-enhanced stimulated
emission. UV lithography and plasma ashing enabled the fabrication of nanodisks
on a wafer-scale, with intended random size variation. Silica-coated nanodisk
particles generated stable sub-nanometer spectra from within biological cells
across an 80 nm bandwidth from 635 to 715 nm.
