A technique for optical coherence tomography is provided. As to a device aspect of the technique, an imaging device comprises a base defining a rotation axis, a scanning and focusing assembly mounted to the base for rotation about the rotation axis, and a drive unit for rotationally driving the scanning and focusing assembly about the rotation axis. The scanning and focusing assembly includes a focusing device for focusing a beam of imaging radiation to produce a focused beam of imaging radiation having a focus, a scanning member for scanning the beam of imaging radiation, and a controller coupled to the drive unit and the scanning member and configured to control the scanning member to cause movement of the focus along a predetermined trajectory with respect to the scanning and focusing assembly.
