Room temperature operation of submicrometre radius disk laser

An InGaAs/InGaAsP quantum well disk laser 0.8 μm in radius and 0.18 μm thick is operated at room temperature in the M = 5 whispering mode at wavelength λ = 1.542 μm using λ = 0.85 μm optical pumping. Because 20% of the spontaneous emission feeds into lasing modes, the output is superlinear with pump over a wide range. A narrow luminescent peak at 1.690 μm wavelength is identified with the M = 4 whispering mode.