Broadband tuning of external cavity bound-to-continuum quantum-cascade lasers

A quantum-cascade structure based on a bound-to-continuum design exhibiting a broad gain curve is presented. The full width at half maximum of the measured luminescence spectrum is 297 cm(-1) at room temperature. Grating-coupled external cavity lasers using this active region could be tuned over 150 cm(-1) (1.45 mum), which is equal to 15% of the free running wavelength (lambdacongruent to10 mum), in pulsed mode at room temperature. Time resolved spectra showed a single-mode operation with a 30 dB side mode suppression ratio after the first 12 ns of the pulse. (C) 2004 American Institute of Physics.