Answer the following problems in detail.
problem 1) Derive an expression for numerical aperture in a step-index fiber. Sketch the intensity pattern for LP12 mode.
problem 2) describe mode control in tunable lasers.
problem 3) find out the responsivity of an InGaAs APD operating at 1.55 (μm and having a quantum efficiency of 0.7 if its gain is 10. How much optical power is needed by this detector to produce 20 nA?
problem 4) describe these in derail: timing jitter, RIN and inter channel crosstalk.
problem 5) prepare a detailed note on code division multiplexing.
problem 6) Describe the different sources those contribute to power penalty in optical links.
problem 7) describe the modulation response of laser for small-signal modulation.
problem 8) Derive an expression for signal-to-noise ratio in APDs.