Comparison of optical to injection excitation in GaAs heterostructure lasers

By using the same GaAs–Ga1−xAlxAs heterostructure material to make both optically excited and junction lasers we have compared the performance of the two classes of lasers under pulsed room-temperature operation. We find that junction lasers have higher differential quantum efficiencies for reasons which are probably inherent in the excitation technique. However, the power efficiencies are higher for the optically pumped samples; by optical excitation of a single heterostructure, we have obtained 20% power conversion efficiency, a factor of 2 better than previous results.