Refractive index sensitivity enhancement of 81° tilted Bragg gratings by cladding etching

Poster: The properties of etched large angle tilted gratings (81o) are investigated. The attenuation peaks of the modes are found to shift to shorter wavelengths at a rate of ∼5nm/min in a solution of 10% HF acid. The most sensitive modes are examined for different etching times creating the relationship that longer etching times results in an increase in overall sensitivity. Comparing the sensitivity of the tilted fibre grating, etched for 6 hours, 506.9nm/unri and the most sensitive LPG, period 164μm, 389.2nm/unri in the RI range 1.30-1.40 shows that the produced tilted grating is more sensitive than the LPG and in this range would ideally be suited for the used in Bio-sensing applications