Fiber optics is a mature technology that has been modified to allow sensing of the environment surrounding the fiber. This includes high-temperature environments found in smokestacks as well as remote sensing.
DifTek has developed a novel fiber-based gas sensor that produces fringing optical fields from the outer surface of a glass capillary which interact with the environment over meter long interaction lengths.
The device is made using unmodified commercially available components and assembly techniques. Using temperature-tuned narrow-band diode lasers, a wide array of important greenhouse gasses can be accurately measured by tuning the laser through an absorption peak of a gas and measuring the differential absorption on- and off-peak. The approach is generally applicable across the entire spectrum for which the glass is transparent (e.g. fused silica or Indium Fluoride).
A very compact sensor can be produced by coiling a long length of the detector. This results in a detector with both a long interaction length and hence high sensitivity in a small volume. The high softening temperature of the sensor and fiber glass allows the device to be used in high-temperature environments such as smokestacks, enabling real-time process control.
The lightweight and rugged construction of the components allow the system to be attached to a drone and used in hazardous environments.