A rotary spectrometer including a plurality of input ports. Each input port may be arranged to receive an optical waveguide carrying electromagnetic radiation. The spectrometer also includes a plurality of optical bandpass filters, which are housed on a first body that rotates under the control of a motor so that each optical bandpass filter may be brought into alignment with each input port. Further, the spectrometer includes a plurality of detector circuits disposed on a second body that rotates with the first body. Each detector circuit is optoelectrically coupled to one of the plurality of optical bandpass filters, thereby resulting in each detector circuit being dedicated to responding to a range of wavelengths determined by the bandpass filter to which it is optoelectrically coupled.