Abstract: A system for on-line optical monitoring of a gas turbine engine includes a viewport into a combustor of the gas turbine engine and an optical filter optically coupled to the viewport. The optical filter is configured to receive broad wavelength band thermal radiation from an interior surface of the combustor while the gas turbine engine is in operation, to substantially block wavelengths of the broad wavelength band thermal radiation emitted and/or absorbed by a flame and/or by exhaust gas within the combustor, and to output narrow wavelength band thermal radiation from the interior surface of the combustor. The system also includes a detector array in optical communication with the optical filter. The detector array is configured to receive the narrow wavelength band thermal radiation and to output signals indicative of a two-dimensional intensity map of the narrow wavelength band thermal radiation.

Abstract: A system for on-line optical monitoring of a gas turbine engine includes a viewport into a combustor of the gas turbine engine and an optical filter optically coupled to the viewport. The optical filter is configured to receive broad wavelength band thermal radiation from an interior surface of the combustor while the gas turbine engine is in operation, to substantially block wavelengths of the broad wavelength band thermal radiation emitted and/or absorbed by a flame and/or by exhaust gas within the combustor, and to output narrow wavelength band thermal radiation from the interior surface of the combustor. The system also includes a detector array in optical communication with the optical filter. The detector array is configured to receive the narrow wavelength band thermal radiation and to output signals indicative of a two-dimensional intensity map of the narrow wavelength band thermal radiation.