A multi-channel wavelength monitor is described that includes a dispersive element that is positioned in an optical path of an incident optical beam having a plurality of wavelengths. The dispersive element disperses the optical beam into a plurality of optical beams that simultaneously propagate in a plurality of optical paths, where each of the plurality of optical beams has one of the plurality of wavelengths. An optical filter is positioned to intercept each of the plurality of optical paths at a plurality of locations. The optical filter substantially passes a respective one of the plurality of optical beams at a respective one of the plurality of locations and substantially blocks the other optical beams. A plurality of optical detectors is positioned adjacent to the optical filter in a direction of propagation of the plurality of optical beams. A respective one of the plurality of optical detectors is positioned in a respective one of the plurality of optical paths. Each of the plurality of detectors generates an electrical signal that is proportional to an intensity of a respective one of the plurality of optical beams.