LAUSR

This paper presents a method of obtaining an operating point configuration for a laser model based on a traveling wave model (TWM), which can then be used in a circuit-level simulator. The method first finds an approximate distributed single-mode stationary solution, this solution is then iterated using the traveling wave equations to an accurate single-mode solution, and finally a short pre-simulation is used to add harmonic content to create a multi-mode configuration of the laser approximating its behavior at an operating point. The effectiveness of this approximation is tested by initiating transient simulations from this operating point and comparing them to the output of the model started from an off state. The stochastic variation in the operating point for a particular configuration is also well predicted. Included in the formulation are gain compression and dispersion effects, laser chirp due to variation in the effective index of the laser mode, and spontaneous emission. Finally, the use of the three-stage process of finding the operating point in a circuit-level simulator is discussed. Not only does the three-stage method provide a quick, accurate operating point for the circuit simulator, but the ability to provide an orders of magnitude faster estimate for the initial circuit-level operating point is critical to the practicality of its use in the simulator. The first stage of the three-stage method does just this.