کنفرانس مهندسی برق ایران

صفحه اصلی / سی امین کنفرانس بین المللی مهندسی برق

The Effect of Cavity Length on Two-State Quantum Dot Laser Performance

نویسندگان :

Gholamreza Babaabasi¹ Mohammad Mohsen Sheikhey² Sara Alaei³

1- موسسه آموزش عالی شهاب دانش قم 2- دانشگاه تبریز 3- دانشگاه تربیت دبیر شهید رجایی

کلمات کلیدی :

modulation bandwidth, Quantum dot Laser, rate equations, cavity length

چکیده :

In this paper, we have investigated a rate equation model to examine the laser cavity length-dependent characteristics of two-state-lasing 1.55µm-InAs–InP (113) B quantum-dot laser (QDL). The rate equations model considered the ground state (GS) and excited state (ES) lasing and the inhomogeneous and homogeneous broadenings. Results demonstrate that by increasing the cavity length, the threshold gain is decreased, the output power spectrum is broadened, the turn-on delay is decreased, and the threshold current is increased for both the GS and ES. Also, the direct relaxation channel does not lead to a saturation of emitted photons of the GS. The photon numbers slope efficiency of the GS emission is reduced when the ES starts to lase, which is more evident for shorter cavity lengths. In addition, With a shorter cavity length, the 3-dB modulation bandwidth increases for both the GS and ES emissions, accompanied by more output photons. Moreover, as the ES lasing began, the 3-dB modulation bandwidth slop of the GS as a function of bias current decreases until it remains almost constant. Also, the 3-dB modulation bandwidth of the GS is larger than ES at the same bias current, where the trend is opposite for larger cavity lengths. The 3-dB modulation responses of ~ 26GHz and ~17GHz have been achieved for GS and ES emission at a bias current of 50mA for 300μm cavity length.