%0 Journal Article %T Single-SectionFabry-Perot Mode-Locked Semiconductor Lasers %A Weiguo Yang %J Advances in OptoElectronics %D 2011 %I Hindawi Publishing Corporation %R 10.1155/2011/780373 %X We present a review of the theoretical models and experimental verification of the single-section Fabry-Perot mode-locked semiconductor lasers based on multiple-spatial-mode (MSM) coupling. The mode-locked operation at the repetition rates of 40£¿GHz and higher and the pulse width of a few picoseconds are confirmed by the intensity autocorrelation, the fast photo detection and RF spectrum, and the optical spectral interference measurement of ultrafast pulse. The spatial mode coupling theory of single-section Fabry-Perot mode-locked semiconductor lasers is also reviewed, and the results are compared with the experimental observations. The small signal modulation response of these lasers, which exhibits high-frequency responses well beyond the relaxation oscillation resonance limit, is also modeled theoretically, and the simulation is verified by the experimental measurements. 1. Introduction Laser is a complex yet self-consistent system that is capable of demonstrating a wide range of dynamic behavior [1]. A simple and special case, where the laser operates in a single frequency continuous wave (cw) constant power operation, has found extensive application in many areas from data storage and retrieval to 3D holography. Mode-locked operation, where multiple longitudinal modes are lasing with time-invariant phase relationship, provides an important way of generating short optical pulse and ultra-stable high-frequency optical clock and also sees a wide range of applications including optical frequency comb generation [2] and nanostructure growth and patterning [3]. A more exotic operation regime, often referred to as the chaotic laser, is also a self-consistent solution of the complex dynamic system. Such novel lasers also start to find increasing interests [4]. These laser applications can almost always appreciate the good device/system features such as small footprint, electrical pumping, and simplicity in control [5]. For example, it was the invention of stable cw semiconductor lasers that made possible optical CD and DVD and optical communication. For the past 40 years, whereas we have almost mastered the art of making stable single-frequency semiconductor lasers through both spatial mode and spectral controls [6¨C8], integrated mode-locked semiconductor lasers remain challenging [9, 10]. The fundamental difficulty comes from the fact that mode-locked operation typically requires action of saturable absorption in the laser cavity [1, 11, 12]. Integrated mode-locked semiconductor lasers seem to inevitably need at least two sections where one provides gain %U http://www.hindawi.com/journals/aoe/2011/780373/