Search

A highly sensitive mid-infrared evanescent wave sensor based on side-polished (SPF) chalcogenide fiber (ChG) was proposed in this work. The optimum optical fiber parameters were determined via numerical simulation by detecting the leakage intensity of evanescent waves from the optical fiber of different polish depths. The SPF remarkably enhanced the evanescent wave sensing while maintaining fiber loss and strength. Graphene oxide (GO) was coated on the fiber to enhance the sensitivity of SPF sensor for butane (C 4 H 10). GO has a great specific surface area and abundant oxygen-containing functional groups, which enlarges the contact area of GO with gas molecules and enables to adsorb gas. Results show that the GO-SPF sensor can be three and five times more sensitive than the original fiber optic sensor and SPF sensor for butane gas detection, and has a fast response time and good repeatability. [ABSTRACT FROM AUTHOR]

Chalcogenide glasses (ChGs) excellent optical materials in the infrared range. ChG lens has important applications in the environmental detection and biochemical imaging field. In this paper, microlens arrays (MLA) with good optical quality were prepared by wet-etching assisted femtosecond laser direct writing technology and 2300 microlenses were prepared in the range of 1 mm2. By controlling the power of laser direct writing and the time of chemical etching, microlenses with diameters ranging from 15 to 70 μm could be prepared. An uniform dense stacked MLA with a small volume in the wavelength range of 0.6–12 μm was achieved. The fabricated MLA has a broad application scenario in cutting-edge mid-infrared fields, due to their tiny size, light weight, high integration, and excellent optical quality. [ABSTRACT FROM AUTHOR]