We address the problem of exact signal recovery in frequency-domain optical-coherence tomography (FDOCT). The standard technique for tomogram reconstruction is the inverse Fourier transform. However, the inverse Fourier transform is known to yield autocorrelation artifacts which interfere with the desired signal. We propose a new transformation for computing an artifact-free tomogram from intensity measurements. Our technique relies on the fact that, in the FDOCT measurements, the intensity of the total signal reflected from the object is smaller than that of the reference arm. Our technique is noniterative, nonlinear, and it leads to an exact solution in the absence of noise. The reconstructed signal is free from autocorrelation artifacts. We present results on synthesized data as well as on experimental FDOC T measurements of the retina of the eye.