A mid infrared spectrometer comprises a high brightness broadband source that generates an output with a broad spectral range in the order of hundreds of wave numbers, a wavelength dispersive element and a detector. In one embodiment, the source comprises an array of semiconductor laser devices operating simultaneously. Each device emits light at wavelength different from the wavelengths emitted by the other devices in the array and the devices are arranged so that the combined output continuously covers the broad spectral range. In another embodiment, each of the lasers in the array is a quantum cascade laser device. In still another embodiment, the quantum cascade laser devices in the array are operated in the regime of Risken-Nummedal-Graham-Haken (RNGH) instabilities. In yet another embodiment, each of the lasers in the array is a mode-locked quantum cascade laser device.