Answer to Question #45489 in Engineering for Golden Young

Question

1. A semiconductor laser has an optical cavity length of 350 μm and an index of refraction of 3.4.
(a) At what wavelengths near 1.55 μm would you expect this laser to emit optical output power?
(b) What is the spacing, in μm, between these different modes of the laser output?

2. A semiconductor laser diode is characterised by measuring its light-current behaviour.
The results show that it emits an optical power output of 2 mW when the diode
current is 50 mA, and its output increases to 4.5 mW when the current is 55 mA.
(a) What is the threshold current of the laser?
(b) When the current is modulated with a square wave digital type signal, with values
I(ave) = 50 mA, I(min) = 40 mA, and I(max) = 60 mA, what will be the maximum and
minimum output optical power levels?