(a) The emission spectrum of the sampled grating device with σ = 50% at peak output power and 10K. The inset shows the lasing spectra for the σ = 30% device at different injection currents. (b) Typical light-current-voltage curves for the 3-mm-long single-mode sampled grating devices at 10K with different sampling duty cycles from 100% to 50%. (c) The output characteristics of the σ = 50% device at different temperatures.