Integrated-optical low-loss PbO2 diffusion waveguide sensitive chemical sensor.

We created an innovated opto-electronic system where integrated-optical sensor, photodetectors, microelectronic comparison scheme, analog-to-digital converter and computer are integrated with the aim to achieve a high sensitivity. The test of this system demonstrates that this sensor can detect the ammonia with the concentration 4 ppm for a signal-to-noise-ratio about 15.