An electrochromic variable optical attenuator having low insertion loss, and which is substantially insensitive to the polarization of optical signals transmitted therethrough, is disclosed. The attenuator includes an annular working electrode, and a counter electrode surrounding and spaced from the annular working electrode in a coplanar configuration. Also included is an electrochromic layer in peripheral contact with the annular working electrode; and a further electrochromic layer overlying the counter electrode. An electrolyte overlies and is in contact with the two electrochromic layers; so that upon application of an electrical voltage between the electrodes, the optical density of the electrochromic layer is altered, thereby varying the attenuation of incident optical signals transmitted therethrough.