Solid-state tapered optical fibre devices

In this paper we report two novel evanescent-field devices based on tapered singlemode optical fibres. In both devices single-mode optical fibre is tapered to waist diameters of around 2 m such that transmission remains close to 100%. In the first device successive coating layers of sol-gel containing fluorescent material are baked on. The major application is in the field of sensing through changes in the absorption and fluorescence characteristics. In the second device, the taper is immersed in a solution of poly(vinyl acetate), also containing fluorescent material. This solidifies, creating a solid-state device. Applications are miniaturized amplifiers and lasers.