Volterra functional series expansions for semiconductor lasers under modulation

Abstract

International audienceAn analytical model based on Volterra nonlinear functionals applied to semiconductor lasers has been developed. Analytical expressions are obtained for different laser diode responses, giving powerful tools for analysis. For harmonic input, the response is given including the gain compression factor ε. Second-harmonic distortion (2HD) shows two maxima at half relaxation oscillation frequency ΩR/2 and at ΩR, in agreement with experiments; the residual dc component due to nonlinearities is estimated and experimentally verified. Dynamic frequency deviation as function of bias current shows resonant characteristics. Relaxation frequency and damping rate ΓR reveal their precise dependence on ε and differential gain A. For step input, the turn-on delay ton and the overshoot PP/Pon expressions of our model are only functions of ΓR and ΩR. PP/Pon, and the ringing phenomena decrease with increasing bias current leve

Reduction of nonlinear distortion in directly modulated semiconductor lasers by coherent light injection

“…Under the above considerations, (1)-(3) gives a set of linearized equations in the frequency domain for , , and , depending on and higher order terms which are combinations of , , and . The obtained formulas can be condensed into the following matrix representation: (9) where the definition if and if has been introduced as well as the definition if and if . The set of are the elements of a matrix of order 3, depending only on the physical and injection parameters and the bias point of the laser.…”

“…The detailed expressions of are given in the Appendix. The quantities , , and are the driving terms that must be specified to determine the solutions of (9).…”

“…Another method of deriving the distortion characteristics of laser diodes is based on equivalent circuit modeling of the active region [6], [7]. Volterra functional series approach can also be used [8], [9] or a limited expansion based on the Bessel function [10], [11]. The Bessel function method has the main interest to be usable in the case of large-signal modulation.…”

Study of dynamic chirp in direct modulated DFB laser for C-OFDR application

“…where a i j are coefficients depending on the physical parameters of semiconductor laser, developed in [20]. We solve this nonlinear equations system by using the Volterra series theory [19][20][21], for the case of strained Multi Quantum Well DFB laser, str-MQW (1550 nm).…”

“…We solve this nonlinear equations system by using the Volterra series theory [19][20][21], for the case of strained Multi Quantum Well DFB laser, str-MQW (1550 nm). We give its physical parameters in Table 1.…”