Extraction of DFB laser rate equation parameters for system simulation purposes

To estimate the performance of lightwave systems based on directly modulated DFB lasers, a rate equation description of the laser is often used. While sophisticated models provide considerable insight into important characteristics of lasers, for system simulations a relatively simple model is often adequate. However, to obtain agreement between experimental and calculated results, values for the parameters appearing in the rate equations must be chosen appropriately. For the purpose of system performance calculations, the rate equation model should reproduce the time variation of the optical power and chirp in response to the modulating current waveform. A technique is described for extracting values for the rate equation parameters based on measurement of the laser threshold current, output power, resonance frequency and damping factor. The objective is to readily determine a set of physically reasonable values for a simple model which reproduces the measured results.