The Micro-Optic Mach-Zehnder Interferometry : Application to the UV Sensors

We propose and demonstrate the UV sensor based on micro-optic Mach-Zehnder interferometer composed of two single mode fiber-pigtailed collimators and a polymer film with photochromic dye. Spirooxazine is used as a UV sensing material which is dispersed in polystyrene and coated on the glass substrate by spin coating method. The extinction ratio and the spectral position of minimum transmission wavelength of fabricated UV sensor can be controlled to be more than 28 dB and 50 nm, independently. The experiment was conducted to measure the wavelength shift of spectral response with UV radiation using the spirooxazine concentration in polystyrene 1.0 wt% and 1.5 wt%. Fabricated UV sensors have a sensitivity of 0.162 nm/mW and 0.316 nm/A.U respectively.