High-frequency modulation characteristics of redVCSELs

Abstract
The authors have measured small- and large-signal modulation response characteristics of a red VCSEL (λ = 670 nm). A small-signal 3 dB bandwidth of 11 GHz was recorded at a bias current of 16 mA. The small-signal response for each bias current was fit to an analytic model to determine the resonance and damping factor. From these data the differential gain coefficient and K-factor were estimated. Large signal digital measurements were conducted showing suitability of this device for data communication applications. An open eye diagram at the receiver output is presented with no pre-bias current applied and the VCSEL modulated at 155 Mbit/s demonstrating the possibility of direct logic-level drive.