An integrated optical hydrogen sensor on a silicon-on-insulator platform: Effects of palladium film thickness

• We design, fabricate and characterize an integrated optical hydrogen sensor on a silicon-on-insulator platform.
• We investigate the effects of palladium film thickness of the hydrogen sensor's performance.
• Sensor response time is short and the hysteresis is low for a thin palladium film.
• The sensor is very compact and its performance compared favorably against many previously reported optical hydrogen sensors.

In this paper, we present the design and experimental demonstration of a silicon-on-insulator based optical hydrogen sensor. We analyze the response time, hysteresis and sensitivity of our device for various palladium film thicknesses. For a 1-nm thick palladium film the response time is approximately 6 s and the sensor suffers little from hysteresis effect. These attractive features make the sensor highly useful for a wide range of applications.