The laser diode current increases
After a minimum threshold current is reached, output power increases linearly with drive current. Figure 1: L-I curve for an 830 nm multimode laser diode showing threshold behavior. As current increases, the Fermi level splits, achieving population inversion and creating gain. It's a critical parameter that defines the laser's sensitivity to external factors. Stimulated emission occurs when a passing photon triggers the recombination of an electron and hole, with emission of a second photon with the same frequency (energy), momentum, and phase. " Below $I_ {th}$, the device operates like a light-emitting diode (LED), producing low-intensity, incoherent light via spontaneous emission.
Read More
