A liquid core waveguide as a refractometer is proposed. Microtunnels were created in standard optical fiber using tightly focused femtoscond laser inscription and chemical etching. A 1.2(h)×125(d)×500(l) µm micro-slot engraved along a fiber Bragg grating (FBG) was used to construct liquid core waveguide by filling the slot with index matching oils. The device was used to measure refractive index and sensitivity up to 10-6/pm was obtained.
© 2007 Optical Society of AmericaFull Article | PDF Article