As demonstrated by Mcintrye,1 low excess noise can be obtained in an avalanche photodiode when the electron and hole ionization coefficients are very different. However, most III-V semiconductors of interest have nearly equal electron and hole Ionization coefficients. Therefore, artificial enhancement of the electron-to-hole ionization rate by using heterojunction superlattice structure has been proposed. Improvement by a factor of 6 when gain equals 10 has been experimentally demonstrated.2 We propose an alternative structure which can also provide low excess noise.
© 1987 Optical Society of AmericaPDF Article