We report high‐resolution absorption spectroscopy of powdered microsamples using a pulsed laser and a gated optoacoustic detection technique. Our method is simple, sensitive, and easily adaptable for cryogenic cooling of the sample. Quantitative data for Ho2O3, Dy2O3, and Er2O3powdered crystals are obtained, and identification and analysis of the observed spectral lines are given for Dy2O3and Er2O3.