(b) How would you design a 1.5 μm edge-emitting semiconductor laser to generate a 40 GHz pulse stream? You should consider factors such as the length of the cavity, the refractive index of the material, and indicate other typical dimensions of the device. How many wavelengths does the cavity length correspond to? (c) Develop a simple numerical model for the 1.5 μm laser you designed in part (b). Use it to demonstrate how the addition of several longitudinal modes leads to the formation of pulses. The model can be based on Python, MATLAB or similar, or even Excel. Use the equation from the lecture notes: E(t) = En expli[(wo+nsw)t + øn]} 11 where wo is an arbitrarily chosen resonant frequency of the cavity and P x E(t)E* (t)