1. A semiconductor laser has a total current that comprises a bias current I(dc) and a small
signal ac current i(ac). The laser threshold current is I(th) = 50 mA. When I(dc) = 75 mA and
i(ac) = 0, the laser output power is P(o) = 2.5 mW.
(a) What is the ac component of the modulated optical power at low frequencies when the laser is driven by a small signal current i(ac) having a peak value of 10 mA?
(b) By means of a sketch, show how you expect the ac component of the modulated
optical power to behave as the frequency of the driving current w(omega) is increased but its amplitude is maintained constant.