Impedance characteristics of mid infra red Quantum Cascade Lasers

This article exhaustively investigates the impedance characteristics of mid-infrared Quantum Cascade Lasers (QCLs). Also, the effect of device parameters namely optical confinement factor, mirror reflectivity and spon-taneous emission factor on the impedance and modulation characteristics of QCLs are reported for the first time. The QCL considered for the study operates at 9 mu m and contains 48 stages. Under standard operating conditions, the device provides an electrical bandwidth of 250 GHz with an intrinsic impedance of 2.07 m Omega. From the analysis results, it is inferred that maximum value of impedance is always achieved with minimum drive current. Moreover, the magnitude of maximum value of impedance (2.37 m Omega) is obtained at a mirror reflectivity (R) of 0.45. Further, maximum bandwidth of 335 GHz is achieved when optical confinement factor (Gamma) is 0.45 and at a drive current of 3 A. The device also provides a flat impedance response with a value of around 1 m Omega over a wide band of frequencies from 1 to 20 GHz enabling its application in 5G wireless networks. Impedance characteristics of QCL will aid in designing proper matching circuits for reducing reflections and efficient operation.

Automated summary

This article exhaustively investigates the impedance characteristics of mid-infrared Quantum Cascade Lasers (QCLs), including the effects of different device parameters on impedance and modulation characteristics, and the optimal performance achieved under various conditions. Understanding the impedance characteristics of QCLs is crucial for designing matching circuits, reducing reflections, and improving device efficiency.