Laser diodes

There are very different kinds of laser diodes (LDs), operating in very different regimes of optical output power, wavelength, bandwidth, and other properties. Please write a report to describe the operating principle and optical properties of LDs for the optical fiber communication system which includes: 1. Edge-emitting LD such as Distributed feedback lasers (DFB lasers) and Distributed Bragg reflector lasers (DBR lasers). 2. Surface-emitting semiconductor lasers (VCSELs). 3. High-power laser diodes (pump for Erbium-doped Fiber Amplifiers(EDFAs)). 4. Emission wavelengths properties (narrower spectral Iinewidths, single frequency, tunable). 5. Beam quality and beam shaping. According to the research of the operating principle and optical properties of LDs, please deduce the technology trends for the next generation of laser diodes for the fiber communication.