Zubaida Abdul Sattar

Wave-Guiding Analysis of Annular Core Geometry Metal-Clad Semiconductor Nano-Lasers

Numerical modeling of cylindrical semiconductor nano-lasers has been undertaken accommodating local gain variations in the active region of the device. Analysis is performed using both the cylindrical transfer matrix method and the finite element method. Calculations have thereby been performed of the modal gain and the lasing condition for the device. The model has been applied to annular active core structures and a comparison has been made of the requirements for achieving lasing via the excitation of TE01 and TM01 modes. For representative structures, it is shown that TE and TM mode lasing can be supported in devices having cavity lengths in the order of 1 and 60 μm, respectively.

External Optical Feedback Effects in Semiconductor Nanolasers

The response of nanolasers subject to external optical feedback has been analyzed. Calculations have been performed using rate equations, which include the Purcell cavity-enhanced spontaneous emission factor F and the spontaneous emission coupling factor β. In the analysis, the influence of F and β is evaluated for varying distance from external mirror, current, and feedback rate. It is observed that, in general, increased F and β at low bias currents increases the critical feedback for which chaos occurs as compared to conventional lasers, whereas at higher bias currents, chaos occurs at lower feedback rates. It is also found that for larger F, when increasing the distance from external mirror, the feedback rate at which chaos occurs increases.

Phase Conjugate Feedback Effects in Nano-Lasers

The response of the nanolasers subject to the phase conjugate feedback (PCF) has been analyzed. Calculations have been performed using rate equations, which include the Purcell cavity-enhanced spontaneous emission factor F and the spontaneous emission coupling factor β. In the analysis, the influence of F and β is evaluated for varying the feedback rate. It is observed that, in general, the onset of chaos occurs at a higher feedback rate for PCF than for conventional mirror feedback (CMF), where PCF has lower intensity noise in comparison with the CMF.

Optical Injection Effects in Nanolasers

The response of nanolasers subject to optical injection has been analyzed. Calculations have been performed using rate equations, which include the Purcell cavity-enhanced spontaneous emission factor F and the spontaneous emission coupling factor β. In the analysis, the influence of F and β is evaluated for varying the injection strength and frequency detuning between the master and slave laser. It is observed that, in general, increased F and β increases the stable locking region and have only a few regions of dynamic instability as compared with conventional semiconductor lasers over a large frequency detuning. It is also found that for larger F, the modulation bandwidths of 90 GHz can be achieved.

Dynamics of nanolasers subject to optical injection and optical feedback

This paper reports theoretical results which delineate a range of nonlinear dynamical behaviours which arise in nanolasers subject to external optical influences. Firstly attention will be given to the impact of external optical feedback on nanolasers. Secondly the dynamical behaviour of semiconductor nano-lasers under external optical injection will be treated. Finally consideration will be given to effects arising in nano-lasers subject to phase conjugate feedback.

Optical feedback effects on the dynamics of semiconductor nano-lasers

Enhanced spontaneous emission effects are shown to increase the sensitivity of semiconductor nano-lasers to optical feedback. These results have significance for the use of nano-lasers in photonic integrated circuits.

Analysis of the large and small signal direct current modulation response up to 60GHz of metal-clad nano-lasers

The response of metal clad nano-lasers to direct current modulation has been analysed in both the small signal and large signal regimes. Calculations have been performed using rate equations which include the Purcell cavity-enhanced spontaneous emission factor, F, and the spontaneous emission coupling factor β. Calculations of both the small signal and large signal direct modulation response of nano-lasers indicate opportunities to achieve modulation bandwidth up to 60 GHz with peak responses at resonant frequencies of order 40 GHz and 30 GHz respectively.