This paper describes a newly designed all-glass miniature (Ø 125 um) fiber-optic pressure sensor design that is appropriate for high-volume manufacturing. The fabrication process is based on the chemical etching of specially-designed silica optical fiber, and involves a low number of critical production operations. The presented sensor design can be used with either single-mode or multi-mode lead-in fiber and is compatible with various types of available signal processing techniques. A practical sensor sensitivity exceeding 1000 nm/bar was achieved experimentally, which makes this sensor suitable for low-pressure measurements. The sensor showed high mechanical stability, good quality of optical surfaces, and very high tolerance to pressure overload.
COBISS.SI-ID: 13269526
This paper presents a maskless micromachining process that can reform or reshape a section of an optical fiber into a complex 3-D photonic microstructure. This proposed micromachining process is based on the etching rate control achieved by the introduction of phosphorus pentoxide into silica glass through standard fiber manufacturing technology. Regions within a fiber cross section doped with phosphorus pentoxide can etch up to 100 times faster than pure silica when exposed to hydrofluoric acid. Various new photonic devices can be effectively and economically created by design and production of purposely doped fibers that are spliced at the tip or in-between standard lead-in fibers, followed by etching into a final structure.
COBISS.SI-ID: 15204374
This paper presents a high-sensitivity, all-silica, all-fiber Fabry- Perot strain-sensor. The proposed sensor provides a long active length, arbitrary length of Fabry-Perot cavity, and low intrinsic temperature sensitivity. The sensor was micro-machined from purposely-developed sensor-forming fiber that is etched and directly spliced to the lead-in fiber. This manufacturing process has good potential for cost-effective, highvolume production. Its measurement range of over 3000 ìå, and strainresolution better than 1 ìå were demonstrated by the application of a commercial, multimode fiber-based signal processor.
COBISS.SI-ID: 15204118
An in-line intrinsic Fabry–Pérot refractive index (RI) sensor is demonstrated. The sensor consists of a short single-mode fiber (SMF) section with removed cladding that is fusion spliced between two lead fibers containing in-fiber mirrors. The measured medium surrounding the decladed fiber section affects the fundamental mode’s effective index and, consequently, the optical path length of the Fabry–Pérot interferometer (FPI). Sensors with different diameters of decladed regions were produced and experimentally evaluated within an RI range of between 1.33 and 1.444. The proposed sensor can be interrogated by standard spectrally resolved interrogators.
COBISS.SI-ID: 15419414
Web-based and adapted e-learning materials provide alternative methods of learning to those used in a traditional classroom. Within the study described in this article, deaf and hard of hearing people used an adaptive e-learning environment to improve their computer literacy. This environment included streaming video with sign language interpreter video and subtitles. The courses were based on the learning management system Moodle, which also includes sign language streaming videos and subtitles. A different approach isrequired when adapting e-learning courses for the deaf and hard of hearing: new guidelines must be developed concerning the loading and display of video material. This is shown in the example of the e-learning course, ECDL (European Computer Driving Licence). The usability of the e-learning course isanalyzed and confirmed using two methods: first, the Software Usability Measurement Inventory (SUMI) evaluation method, and second, the Adapted Pedagogical Index (AdaPI), which was developed as part of this study, and gives an index to measure the pedagogical effectiveness of e-learning courses adapted for people with disabilities. With 116 participants, of whom 22 are deaf or hard of hearing, the e-learning course for the target group has been found suitable and appropriate according to both evaluation methods.
COBISS.SI-ID: 15701526