Figure 3

From: Mid-infrared surface transmitting and detecting quantum cascade device for gas-sensing

Figure 3

Prototype sensing setup (a) with the sensor, the lens for beam collimation, the chopper and the flat mirror. The distance between the mirror and the device is 440 mm. Separate FTIR characterization scheme (b) of the detector element and the laser using the internal globar source and the (deuteriated triglycinesulfate) DTGS detector of the spectrometer respectively. The chopper is used for detector characterization only.