Аннотация:In-plane birefringent porous Si (PSi) layers formed from heavily boron-doped (110) Si wafers are investigated by using polarization-resolved infrared absorption (IR) spectroscopy. The absorption by free charge carriers and by Si-Hx (x = 1, 2, 3) surface bond vibrations are found to exhibit strong anisotropy (dichroism), which originates from the form anisotropy of Si nanocrystals assembling (110) PSi layers. The free carrier absorption dichroism is explained by using the effective medium approximation and classical Drude model and considering additional carrier scattering in anisotropically shaped Si nanocrystals.