Measurement of gas diffusion coefficient using photonic crystal fiber

We report the use of photonic crystal fiber (PCF) for the measurement of gas diffusion constant. PCF has uniform airhole columns along the fiber length that provide the basis for the study of gas diffusion based on the capillary method. The gas concentration within the airhole columns is monitored by measuring the attenuation of light through the PCF caused by the evanescent wave absorption of light by the gas sample.