Quantum well lasers in telecommunications

Quantum well (QW) lasers are semiconductor lasers that use the special two-dimensional physical properties of very thin semiconductor layers in their light emitting regions to enhance their performance. The superior performance of the QW laser has made it the laser of choice for future lightwave communications systems. This paper deals historically with the concept of the QW laser by first looking in depth at its major antecedent, the bulk active diode laser. It then turns to the specific properties and advantages of the QW laser in modern optical communications systems, and studies the fabrication of QW lasers. Finally, the paper briefly explores future directions in QW laser research.