Abstract: An optical device including an optical amplifier to amplify optical signals received through an optical input, and to supply the amplified optical signals from an optical output, and an optical filter coupled to the optical amplifier. The optical filter changes the gain slope of the optical amplifier in response to a change in a single parameter of the optical filter. The single parameter may be a change in a central wavelength of the optical filter function. The optical filter preferably has a parabolic spectral function. The single parameter may be varied as a function of temperature such that the variable optical attenuator compensates for variations in the gain spectrum of the optical amplifier that occur as a function of operating temperature.

Abstract: An optical spectrometer includes an echelle array disposed in the path of a light signal so as to diffract the incident light signal. The light signal falls within a predetermined wavelength band centered about a central wavelength. The echelle array has a plurality of diffraction scattering sites periodically spaced apart by a distance of at least about five times the central wavelength. The spectrometer further includes a photodetector array positioned to receive a far-field diffraction pattern produced by the diffracted light from the echelle array and to output electrical signals representing the spatial pattern and relative intensity of the far-field diffraction pattern. Additionally, the spectrometer includes a processing circuit coupled to the photodetector array for processing the electrical signals to determine the power spectrum of the light signal.