TAILIEUCHUNG - Laser điốt được phân phối thông tin phản hồi và các bộ lọc du dương quang P3

The introduction of semiconductor lasers has boosted the development of coherent optical communication systems. With the built-in wavelength selection mechanism, distributed feedback semiconductor laser diodes with a higher gain margin are superior to the Fabry– Perot laser in that a single longitudinal mode of lasing can be achieved. In this chapter, results obtained from the threshold analysis of conventional and singlephase-shifted DFB lasers will be investigated. In particular, structural impacts on the threshold characteristic will be discussed in a systematic way. . | 3 Structural Impacts on the Solutions of Coupled Wave Equations An Overview INTRODUCTION The introduction of semiconductor lasers has boosted the development of coherent optical communication systems. With the built-in wavelength selection mechanism distributed feedback semiconductor laser diodes with a higher gain margin are superior to the Fabry-Perot laser in that a single longitudinal mode of lasing can be achieved. In this chapter results obtained from the threshold analysis of conventional and singlephase-shifted DFB lasers will be investigated. In particular structural impacts on the threshold characteristic will be discussed in a systematic way. The next two sections of this chapter present solutions of the coupled wave equations in DFB laser diode structures. In section the concepts of mode discrimination and gain margin are discussed. The threshold analysis of a conventional DFB laser diode is studied in section whilst the impact of corrugation phase at the DFB laser diode facets is discussed in section . By introducing a phase shift along the corrugations of DFB LDs the degenerate oscillating characteristic of the conventional DFB LD can be removed. In section structural impacts due to the phase shift and the corresponding phase shift position PSP will be considered. As mentioned earlier in Chapter 2 the introduction of the coupling coefficient k into the coupled wave equations plays a vital role since it measures the strength of feedback provided by the corrugation. In section the effect of the selection of corrugation shape on the magnitude of k will be presented. With a 2 phase shift fabricated at the centre of the DFB cavity the quarterly-wavelength-shifted QWS DFB LD oscillates at the Bragg wavelength. However the deterioration of gain margin limits its use as the current injection increases. This phenomenon induced by the spatial hole burning effect which is the major drawback of the QWS laser structure will be examined at .

• Kĩ thuật Viễn thông
• Laser điốt
• phân phối laser
• bộ lọc du dương
• thông tin phản hồi
• laser thông tin