Optical Humidity Sensor Using a Narrow Band-Pass Filter Prepared by Glancing Angle Deposition

This paper reports a study of an optical humidity sensor which gives a sensible response to various humidity conditions. The optical humidity sensor can be obtained through nanoscale porosity variations produced by using a physical vapor deposition technique known as glancing angle deposition (GLAD). The optical humidity sensor made of narrow band-pass filter (NBPF) is fabricated by the GLAD technique. The transmittance spectrum of this sensor shifts due to a change in the effective refractive index of the porous microstructure, resulting from water-vapor adsorption/desorption at various humidity conditions. The sensitivity, the hysteresis and the response time properties of the sensor are also studied. KCI Citation Count: 3