Abstract: An analog position indicating optical encoder is provided including: an element (1) with a band (2) having a transparency which substantially is complete with respect to two wavelengths (1.sub.1 and 1.sub.2) but varies as a function of the angular or linear distance for a third wavelength (1.sub.3) at wavelength which is between the above-said two wavelengths (1.sub.1 and 1.sub.2); light emitting means (3.sub.1,3.sub.2,3.sub.3) emitting three light beams (7.sub.1,7.sub.2,7.sub.3) at the above said wavelengths (1.sub.1,1.sub.2,1.sub.3); a first optical coupler (5,6) mixing the beams (7.sub.1,7.sub.2,7.sub.3); optical bidirectional transmission means of the optical fiber type (B); a second optical coupler (18,19) dividing into three beams (20.sub.1,20.sub.2,20'.sub.3) the light leaving the means (B) after being reflected by the optical element (13) and after passing through the band (2); three readers (23.sub.1,23.sub.2,23.sub.3) responsive to the wavelength (1.sub.1,1.sub.2, and 1.sub.