The invention concerns an optical imaging apparatus comprising (o) a light source (1) , (p) sample holding means, (q) an interferometer, (r) reference means, (s) an objective (8) which is adapted to have its sample side focal plane crossing a sample held in said sample holding means, (t) optical or electro-optical means (2, 3, 5, 16) adapted to produce a ring shaped or multi-spot light source in the front focal plane (17) or any conjugated plane (17') of said objective (8) , at least one detector. The invention also includes a method for using said apparatus where the sample is illuminated by an interference pattern and the depth information is obtained by using optical Coherence Tomography.