Measuring the Chirp and the Linewidth Enhancement Factor of Optoelectronics Devices Based on a Mach-Zehnder Interferometer

In this paper, a technique based on the use of a Mach-Zehnder interferometer is proposed in order to evaluate chirp properties of optoelectronic devices. When the device is modulated, this experimental set-up allows extracting the component's response of amplitude modulation (AM) and frequency modulation (FM) that can be used to obtain the value of the H-factor. As compared to other techniques, the proposed method gives the sign of the Hfactor without requiring any fitting parameters and thus is a reliable tool, which can be used for the characterization of high-speed properties of semiconductor diode lasers and electroabsorption modulator. Comparison with widely accepted fiber transfer function method is also performed with very good agreement.