Abstract

Optical-grating experiments have been shown to be a powerful probe of carrier diffusion.¹ In these experiments two beams interfere in a material, forming a grating that is probed by a third beam. The. decay of the optically created population grating occurs through many channels, such as recombination γ_rec and spatial diffusion. For diffusion independent of position and concentration, the decay due to spatial diffusion is governed by Pick's Law and the diffusion coefficient D is extracted by measuring the grating decay Γ versus the grating spacing Λ, with Γ = γ_rec + (4π²D/Λ²).

© 1995 Optical Society of America