Research On L-Band EDFL And Tunable EDFL

The optical fiber amplifiers and tunable light sources are key components in thedense wavelength division multiplexing(DWDM) transmission system. My paper isconcentrated on the research of L band EDFA and tunable EDFL.(1) R&D of LD power1 Based on analog circuits, a LD power with a new constant current source design isintroduced, which includes two transistors in series that can be adjusted as a whole.The damage to the expensive LD caused by the sudden invalidation of onetransistor can be avoided, thus saving the complex high speed protection circuit.2 With a singlechip C8051-F005 as the core, a digital LD power is designed.With thesinglechip incorporated, it makes it quicker to finish the design and also makes ourmachine compact.(2) Theory analysis and experiment on L band EDFA1 The building-up process of a EDFA theory model based on two level system andEr³⁺ homogeneously broadening is explained in detail. With the ESA or Er³⁺-Er³⁺ interaction effets taken into consideration, theory model for L-EDFA isconstructed respectively.2 With OptiAmplifier 3.0, we analyze the amplification properties and intrinsic gainflat property of L band EDFA, putting forward intrinsic gain formula under twoconditions, which is helpful to the succedent design.3 With analysis of the properties of dual-stage L-EDFA, we optimize the design. Weget an intrinsic flat gain of 25 dB and NF 5 dB, which is accordant to thesimulation.(3) Research on tunable erbium doped fiber laser (EDFL)1 A wavelength-selectable discretely tunable erbium-doped fiber laser in C band isfabricated using a precise multi-wavelength grid filter(Hi-Bi FLM) and achannel-selecting tunable filter.With 41 channel operation of ¹00GHZ channelspacing, the laser is suitable for DWDM.