Tunable fiber laser based on an etched fiber Bragg grating

Abstract

tively, and can satisfy the typical bandwidth requirement for dualband WLAN applications.The measured radiation patterns for the proposed antenna at 2.45 and 5.25 GHz are shown in Figures 3 and 4, respectively. It can be seen that the radiation patterns at both frequencies have monopolelike radiation patterns. However, in the azimuthal plane ( x-y plane), the radiation patterns at 2.45 and 5.25 GHz are more similar to omnidirectional radiation. The measurements at the other operating frequencies have similar radiation patterns, as shown in Figures 3 and 4. Figures 5(a) and 5(b) show the antennagain responses measured in the 2.4-and 5.2-GHz bands, respectively. For the 2.4-GHz band, the peak antenna gain is about 1.98 dBi and the gain variation is less than 0.3 dBi. As for the 5.2-GHz band, the peak antenna gain is about 3.95 dBi and the gain variation is within 0.4 dBi. The antenna-gain variations in both bands are actually quite small.

Enhanced sensitivity of an in-fibre Bragg grating pressure sensor achieved through fibre diameter reduction

“…The etching process was stopped by removing the fibre from the HF bath and immediately submerging it into a saturated aqueous solution of calcium hydroxide for 10 min. Previous investigators have shown that Bragg grating optical performance is not compromised by acid etching [27,28] to diameter as small as 25 μm [29]. However, it has also been shown that fibre optic cables stripped of their polyimide coating suffer from reduced failure and fatigue strength [11].…”