Reported is optical limiting in the near-ir using composites consistin
g of quantum-confined nanocrystals of InP in porous Vycor glass. The n
onlinear optical properties of the InP-doped glasses, investigated usi
ng the Z-scan technique, were characterized by a negative nonlinear in
dex, absorption-induced negative refraction due to carriers, and nonli
near loss due to two-photon absorption and excited state absorption of
carriers.