Abstract: The invention relates to different aspects of a photodetector (1-8) for detecting electromagnetic radiation in a spectrally selective manner, comprising a first optoelectronic component (100-106, 108) for detecting a first wavelength of the electromagnetic radiation. The first optoelectronic component (100-106, 108) has a first optical cavity and at least one detection cell (21, 21a, 22, 22a, 23) arranged in the first optical cavity. The first optical cavity is made of two mutually spaced parallel mirror layers (11, 11a, 11?, 12, 12a). The length of the first optical cavity is configured such that for the first wavelength, a resonant wave (13, 13a), which is associated with said wavelength, of the i-th order is formed in the first optical cavity.