Abstract

Optical signals generated by gain-switching (GS) or direct modulation of semiconductor lasers exhibit a significant frequency chirp due to the intrinsic dynamics of the device. Simple time-resolved techniques for the characterization of the frequency chirp are required in order to optimize the device and system performances, especially in telecommunication applications. Different linear and non-linear high-speed techniques have been proposed for the full characterization of an optical field [1]. Recently, a new method based on the phase recovery from ultrafast optical differentiation (PROUD) has been proposed by Li et al. [2]. The method is based on the differentiation of the optical pulse and the recovery of the derivative of the phase by applying a simple non-iterative formula to the measured intensities of the pulse at the input and output of the differentiator. Optical differentiation can be implemented by means of different types of all-fiber or bulk interferometers [3].

© 2011 Optical Society of America