Aragon Photonics Labs' complex optical spectrum analyzer (OCSA), measuring both the amplitude and phase of an optical signal in nearly real time, will be demonstrated at OFC/NFOEC. The instrument uses a new method based on stimulated Brillouin scattering filtering and heterodyne detection, with potential applications in which phase and amplitude of optical signals are relevant, such us analysis of phase modulation formats, pulsed lasers or chirp measurements.