We studied the optical absorption, polarized reflectance (PR) and photoluminescence (PL) of beta-FeSi2 single crystals grown from solution. In low-absorption measurements, we found a phonon emission and absorption structure, which suggests an indirect transition. The exciton energy gap of 0.814 eV was determined from the absorption spectrum at 3.5 K. We also found a direct transition with the gap energy of 0.939 eV. PR measurements for E//a, E//b and E//c revealed the anisotropy of reflectivity of beta-FeSi2. We observed the PL with a peak wavelength of about 1.56 mum at 20 K. (C) 2004 Elsevier B.V All rights reserved.