Circuit modeling for the simulation of semiconductor lasers

Khoo, Kay Leong (2006) Circuit modeling for the simulation of semiconductor lasers. Universiti Malaysia Sabah. (Unpublished)


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The main objective of this thesis is to perform simulation studies on double-heterojunction (DH) injection lasers and quantum-well (OW) lasers. Circuit level modeling of these laser models is presented in this thesis. Simulation studies provide analytical observation on the behavior of actual laser structures and to ensure that the device is fully operational before its actual fabrication. The circuit models presented provides a fast and accurate simulation tool with little computational complexity for large and small signal behavior. Rate equation based laser models have been simulated using PSPICE simulator. DH laser model is derived using rate equations for single mode operation and later expanded to multimode operation. The DH laser model consists of mainly discrete components. Detailed analysis is carried out on both large and small signal circuit models. The two port circuit model includes the effect of chip and package parasitics, space-charge capacitance, electrical drive circuit and electro-optical dynamics of the active layer. The modulation response, light-current characteristic and transient behavior of the DH lasers are studied. Simulated response is obtained by varying different parameters of the rate equations. It has been observed that spontaneous emission coefficient contributes Significantly to the turn on delay and damping of relaxation oscillation. The effect of source resistance on the frequency response is also studied; the occurrence of second resonance peak at higher frequency has been observed. Detailed description of linearization performed on large signal model in order to obtain the small signal ac circuit model is also presented. The procedure outlined in this thesis serves as a general guideline for any attempt on linearization of any type of large signal laser circuit models. Finally, the effects of gain compression and various parameters of small signal model on modulation response are also studied. A single mode large Signal OW laser model is presented. QW laser demonstrates Significant reduction in magnitude of threshold current as compared to conventional semiconductor lasers. Bias current imposes limit on turn on delay and relaxation oscillation of light output response of OW laser. Also, it is demonstrated that increases in carrier transport time across the separate confinement heterostructure (SCH) region has complementary effect on resonance peak and -3db bandwidth of modulation response. The simulation results presented in this thesis agree well with existing published work. The laser model can be applied in the design and simulation of microwave optical fiber link (GHz range), optoelectronic integrated circuits (OEIC) and photonic devices.

Item Type: Academic Exercise
Uncontrolled Keywords: double-heterojunction (DH), quantum-well (OW), injection laser, simulation, rate equation, circuit model
Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
Divisions: SCHOOL > School of Engineering and Information Technology
Date Deposited: 24 Jun 2014 00:49
Last Modified: 13 Oct 2017 04:55

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