The invention relates to wavelength selective optical components for transmitting the light in a narrow spectral band, which is centered around a wavelength, and for reflecting the wavelengths lying outside this band. The component includes an input guide (2) conducting light radiation (3) to a tunable filter (1), an input guide (2) conducting the radiation (3) to the filter (1) in order to perform a first pass through it. The component includes means (6) for returning a first part (4) of the radiation (3) reflected by the filter (1) during the first pass in order to perform a second pass through it.