in this work, an optical sensor for detection of ascorbic acid is described. the sensor is fabricated by casting and spin-coating silica sol-gel doped with 2,6-dichlorophenol indophenol on the glass plates. the sols are in turn obtained by acidic hydrolysis of various precursors such as tetraethoxysilane, triethoxymethylsilane and triethoxyoctylsilane in the presence of 2,6-dichlorophenol indop...

Polishing abrasives that have been bound in a solid matrix can offer several potential advantages over loose-abrasive processes with pitch or polyurethane laps for finishing of optics. These advantages include polishing efficiency, temperature stability, cost of consumables, and compatibility with computer numerically controlled generating machines. Unfortunately, little has been published on b...

We present improvements to fluorescence sensing in soft-glass microstructured optical fibers that result in significantly improved sensitivity relative to previously published results. Concentrations of CdSe quantum dots down to 10 pM levels have been demonstrated. We show that the primary limitation to the sensitivity of these systems is the intrinsic fluorescence of the glass itself.

We report on the optical spectroscopy of monolithic fiber preform prepared from nanoporous bismuth-doped silica glass. The experiments reveal the existence of at least two different types of active centers and clearly demonstrate that the presence in the glass matrix of other dopant is not necessary to obtain the near-IR photoluminescence connected to Bismuth.

Optical glasses are optimized to provide excellent transmittance throughout the total visible range from 400 to 800 nm. Usually the transmittance range spreads also into the near UV and IR regions. As a general trend lowest refractive index glasses show high transmittance far down to short wavelengths in the UV. Going to higher index glasses the UV absorption edge moves closer to the visible ra...

A new method for creating microcantilevers in glass allows integration of optical waveguides and Bragg gratings. Devices are fabricated by high precision sawing, followed by direct UV writing of waveguides with Bragg gratings and then chemical etching to release the freestanding glass structures. Optical measurement of the Bragg gratings together with piezo-actuation allows the mechanical reson...

Despite being close neighbors on the Periodic Table, selenium and tellurium present a totally different abilities to form glasses. Se is a very good glass former, and gives rise to numerous glass compositions which are popular for their transparency in the infrared range and their stability against crystallization. These glasses can be shaped into sophisticated optical devices such as optical f...

Superficially coloured lead crystal glass was obtained by ion-exchange with silver. Both red and yellow ruby colouring were achieved by the presence of small silver particles (colloids) dispersed into the ion-exchanged glass surface. Direct silver ion-exchange of the glass yielded yellow colouring (optical absorption around 410 nm). Silver ion-exchange of lead glass previously doped with a redu...

Chalcogenide glasses are based on sulfur, selenium and tellurium elements, and have been studied for several decades regarding different applications. Among them, selenide glasses exhibit excellent infrared transmission in the 1 to 15 µm region. Due to their good thermo-mechanical properties, these glasses could be easily shaped into optical devices such as lenses and optical fibers. During the...