Motivated by the potentially large number of devices and simulations involved in optoelectronic system design, and the associated need for compact optoelectronic device models, we present a simple thermal model of vertical-cavity surface-emitting laser (VCSEL) light-current (LI) characteristics based on the laser rate equations and a thermal offset current. The model was implemented in conventional SPICE-like circuit simulators, including HSPICE, and used to simulate key features of VCSEL LI curves, namely, thermally dependent threshold current and output-power roll-over for a range of ambient temperatures. The use of the rate equations also allows simulation in other non-dc operating regimes. Our results compare favorably to experimental data from three devices reported in the literature.

The increasing interest in vertical-cavity surfaceemitting lasers (VCSEL's) requires the corresponding development of circuit-level VCSEL models for use in the design and simulation of optoelectronic applications. Unfortunately, existing models lack either the computational efficiency or the comprehensiveness warranted by circuit-level simulation. Thus, in this paper we present a comprehensive circuit-level model that accounts for the thermal and spatial dependence of a VCSEL's behavior. The model is based on multimode rate equations and empirical expressions for the thermal dependence of the activelayer gain and carrier leakage, thereby facilitating the simulation of VCSEL's in the context of an optoelectronic system. To confirm that our model is valid, we present sample simulations that demonstrate its ability to replicate typical dc, small-signal, and transient operation, including temperature-dependent lightcurrent (LI) curves and modulation responses, multimode behavior, and diffusive turn-off transients. Furthermore, we verify our model against experimental data from four devices reported in the literature. As the results will show, we obtained excellent agreement between simulation and experiment.

Carrier diffusion and spatial hole burning can have a severe impact on vertical cavity surface emitting laser (VC-SEL) performance. In particular, these phenomena can produce secondary pulses, bumps, and optical tails in the VCSEL turn-off transient which limit both the system bit rate and the bit error rate (BER). To study these effects, laser rate equation models that include both spatial and temporal dependence are often employed; however, simulations which require discretization of both space and time, while accurate, typically consume vast amounts of computational power. In this paper, we demonstrate that models based on well-accepted spatially independent rate equations can be used to simulate these effects. These models exhibit the advantages of the full spatio-temporal approach but execute much more quickly. We also integrate these models into electronic computer-aided design (CAD) tools which will enable circuit and system designers to simultaneously simulate electrical and optical performance.

The standard theory for photoreceiver noise unrealistically defines the system transfer function solely in terms of the input and output pulse shapes, based on the assumption that equalization is provided at receiver output. Most phoends and do not include equalizers, making direct application of the conventional noise expressions inappropriate. Even if equalization is provided, a signal-dependent definition of the transfer function will be accurate only under certain limited conditions. Furthermore, it is unrealistic to assume a given pulse shape at the input. In this paper we consider the effect of incorporating a more realistic transfer function into the conventional noise theory. We choose the transimpedance amplifier for our analysis due to its widespread popdariw, however, our approach is general and can be applied to a broad class of photoreceivers. Since our transfer function is based on a physical circuit, our results can be used to estimate photoreceiver noise performance without making any assumptions on the input or output pulse shapes. toreceivers reported in the litera P re, however, are only front