SMOGLESS — Optical gas measurement system
Product description
National Collaborative Project 2021-2023 ✓ Completed
The SMOGLESS project aims to develop an embedded optical gas monitoring system for severe aeronautics conditions.
In collaboration with Institut Foton, the SMOGLESS project validated that specific MIR wavelengths are ideally suited for measuring CO, CO₂, NO, and NO₂ in multigas combustion flows.
This advanced monitoring system employs absorbance measurement technology, leveraging innovative Silica Anti-Resonant Fibers (ARF) that guide light at 4µm – 5µm Mid-Infrared (MIR) wavelength range and with a very high temperature resistance (<1000°C).
The system is built to withstand severe conditions, such as high temperatures and pressures, vibrations and the presence of pollutants, making it ideal for demanding aeronautic environments. By implementing this system, the project seeks to reduce fuel consumption, lower air pollution, and monitor engine aging effectively.
SMOGLESS represents a successful European collaboration between photonics experts and aeronautics specialists, bringing together complementary expertise to create an innovative solution.
- Photonics Bretagne: Developed specialized optical fiber capable of transmitting infrared light at very high temperatures (up to 600°C), essential for near-engine operation.
- Institut FOTON: French laboratory expert in photonics and optical sensors. Contributed optoelectronics expertise for test benches and first experimental validations.
- IDIL Fibres Optiques: French expert in optical and photonic systems. Ensured complete system integration: probe design, laser shaping, rack mounting, and final demonstrator production.
- SOURIAU: Manufacturer of high-performance, high-reliability interconnection solutions for severe environments. Key role on aeronautical aspects, providing expertise on constraints (vibrations, temperature, size) and specifications definition.
- End users: Safran and Airbus
KEY ACHIEVEMENTS
- Multi-gas monitoring: Real-time measurement of CO, CO₂, NO, NO₂ in kerosene combustion flow
- Extreme temperature: Operating near the turbine where temperatures can exceed 1000°C, requiring specialized fiber optics (anti-resonant fiber) that don’t degrade (600°C validated in testing)
- Vibration resistance: Constant vibrations during flight requiring robust anti-vibration mounting and shock resistant components
- Space constraints: Severely limited installation space in aircraft engines demanding miniaturized, compact system design
- Measurement method: Standard optical fiber are opaque at 4.3µm wavelength – requiring innovative hollow-core fiber technology
- Real-time precision: Providing accurate, instantaneous measurements to pilots for combustion optimization. Enables fuel consumption optimization and emission reduction
OPTICAL TECHNOLOGY
IDIL developed the entire embedded system comprising:
- Optical Interrogator: Laser source and signal processing electronics
- Optical Harness: Custom-designed fiber optic cabling using ARF for high-temperature signal transmission
- Optical Probe (Transducer): Measurement head positioned near the aircraft turbine
TECHNICAL SPECIFICATION SUMMARY
| SMOGLESS (AeroCo₂Sensor) | |
| Measured gases | CO, CO₂, NO, NO₂ (simultaneous) |
| Wavelength range | 3.8–4.7 µm (Mid-Infrared) |
| Primary wavelength | 4.3 µm (CO₂ optimized) |
| Detection limit | <10 ppm (gas-dependent) |
| Measurement range | ppm to percentage levels |
| Response time | < 100 ms |
| Temperature range | Up to 1000°C (probe environment) |
| Vibration tolerance | Aerospace qualification levels |
| Fiber type | Silica Anti-Resonant Hollow Core (ARF) |
| Optical loss | 0.19 dB/m @4.3 µm |
| Bend radius | < 5 cm (no loss) |
| Temperature rating | 600°C validated, 1000°C design target |
| Core guidance | Air-core (hollow) |
APPLICATIONS
The SMOGLESS system is designed for optical monitoring of combustion gases in extreme environments. Thanks to its silica anti-resonant hollow core fiber, SMOGLESS withstands extreme temperatures (<1000°C), vibrations and polluted environments, where traditional sensors cannot operate.
- Aeronautics: aircraft turbine emissions
- Industrial energy: emission control in gas turbines and thermal power plants
- R&D: engine test benches, high-temperature combustion studies and sustainable fuel development (SAF)
