Problems and solutions

Calculation problems and short questions from old exams Solutions and answers CALCULATION PROBLEMS AND SHORT QUESTIONS OPTICAL FIBRES Problems Short questions SOLUTIONS OPTICAL SOURCES AND TRANSMITTERS 30 Problems 30 Short questions 33 SOLUTIONS 34 OPTICAL DETECTORS AND RECEIVERS 50 Problems 50 Short questions 53 SOLUTIONS 54 LIGHTWAVE SYSTEMS 66 Problems 66 Short questions 67 SOLUTIONS 68 OPTICAL AMPLIFIERS 73 Problems 73 Short questions 76 SOLUTIONS 77 DISPERSION COMPENSATION 93 Problems 93 SOLUTIONS 94 MULTICHANNEL SYSTEMS 99 Problems 99 Short questions 99 SOLUTIONS 101 SOLITONS 103 Problems 103 Short questions 103 SOLUTIONS 104 10 COHERENT LIGHTWAVE SYSTEMS 106 Problems 106 Short questions 106 SOLUTIONS 108 Almost all of the problems and solutions are translations, from Swedish into English, of old exams The problems is ordered in chapters, which follow the course book Optical fibres Problems Wave propagation 2.1 A single mode fibre is to be dimensioned The normalised frequency is 80 % of the maximum allowed for single mode condition The relative refractive index difference is 0.005 and the refractive index of the core is 1.5 The wavelength is 1.5 μm Determine the radius of the core Calculate numerically also the ratio between the intensity at the centre of the core and the intensity at the surface of the cladding (Exam 960830) 2.2 A standard single mode fibre is to be characterised The refractive index of the core is 1.44 and the relative refractive index difference is 10-3 The fibre is to be used at 1.7 μm and has the normalised frequency of How large is the diameter of the core? How much of the power is transported in the core? What is the material dispersion parameter? What is the minimal attenuation? (Exam 970411) 2.3 Calculate numerically the field intensity of the fundamental mode in a fibre, however normalised to the field intensity of the midpoint of the core The radius of the core is a = μm and its refractive index is 1.5 The relative refractive index difference is 0.005