We have investigated the conductivity of equilibrium and photoexcited electrons in nanoporous indium phosphide (InP) of various porosities and of two orientations: (100) and (111). We observed an enhanced transmission through the nanoporous samples compared with bulk InP, resulting from a suppression of the conductivity by the pores. The frequency-dependent conductivity was extracted numerically from the transmission data. We examined the dynamical conductivity of photoexcited carriers using ...