| Popis: |
In this chapter, we discuss the possibility of quantum dot (QD) laser and QD semiconductor optical amplifier (SOA) applications in ultra-wideband (UWB) communication systems. We mainly concentrate on novel methods of UWB pulse photonic generation, UWB over optical fiber (UROOF) technology, and in particular, performance of analogous optical links in UROOF systems. We demonstrate that QD devices are promising candidates for different applications in the communication systems due to their low bias current, high temperature stability, extremely high operation rate, and the possibility of the light generation in a wide range of optical frequencies. We briefly discuss the state-of-the-art in UWB technology and present original results concerning UWB pulse photonic generation based on passive elements, and application of a QD laser in an analogous optical link. The chapter is constructed as follows. In Section 2, we discuss the UWB communication stateof-the-art. In Section 3, we discuss the photonic generation of the UWB pulses and present original experimental results concerning the generation of UWB Gaussian pulses with passive elements. In Section 4, we describe the novel approach to UWB communication systems known as UROOF technology which permits to increase dramatically the distance of the UWB signal transmission and to improve the UWB system performance. In Section 5, we analyze the structure and performance of an analog optical link as a key element of the UROOF communication system. The improvement of the analog optical link performance, especially with respect to operation rate and bandwidth, can be achieved by implementation of integrated photonic and electronic circuits. The possibilities of Si photonics applications in UROOF technology are discussed in Section 6. The key element of UROOF communication system is a laser diode as a source of a directly modulated optical carrier. The structure, operation principle and dynamics of QD lasers are discussed in Section 7. We have carried out numerical simulations for the analogous optical link with the QD laser instead of a conventional vertical cavity surface emitting laser (VCSEL) using the coupled rate equations. The theoretical results predict a high performance of such a link. Conclusions are presented in Section 8. 5 |
