By measuring the frequency-noise power spectral density of a cryogenically-cooled mid-infrared quantum cascade laser, we investigate the different contributions to the noise spectrum and identify the main differences with respect to standard bipolar semiconductor devices. In particular, the existence of a thermal cut-off on the 1/f noise allows to identify the current fluctuations through the heterostructure as the physical mechanism, intrinsic to the device, at the basis of the measured flicker noise. This result, marking the difference with bipolar semiconductor devices, is confirmed analyzing the laser frequency response to a modulation of the driving current.
Frequency-noise dynamics of mid-infrared quantum cascade lasers
Borri Simone;Bartalini Saverio;Cancio Pastor Pablo;Galli Iacopo;Giusfredi Giovanni;Mazzotti Davide;De Natale Paolo
2011
Abstract
By measuring the frequency-noise power spectral density of a cryogenically-cooled mid-infrared quantum cascade laser, we investigate the different contributions to the noise spectrum and identify the main differences with respect to standard bipolar semiconductor devices. In particular, the existence of a thermal cut-off on the 1/f noise allows to identify the current fluctuations through the heterostructure as the physical mechanism, intrinsic to the device, at the basis of the measured flicker noise. This result, marking the difference with bipolar semiconductor devices, is confirmed analyzing the laser frequency response to a modulation of the driving current.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
