The present invention is directed to method and apparatus for measuring the spectral characteristics of an object from a formed object generated input signal. The method comprises the steps of directing the input signal onto a diffraction grating. Diffracted signals are directed to a resonant mirror assembly for sequentially focusing a select diffracted signal. From that focused select diffracted signal, a spectral characteristic of said object is determined. Each said spectral characteristic is associated with each corresponding focused select diffracted signal and the associated signals are published. The apparatus is an improved spectrometer comprising a fiber cable assembly for receiving an object generated input signal and a diffraction grating. A resonant mirror assembly sequentially focuses a select diffracted signal, a sensor sensing which diffracted signal has been focused from the diffraction grating. An analyzer coupled with the sensor determines a spectral characteristic of the object from said select diffracted signal.