High resolution compact spectrometer system based on scattering and spectral reconstruction.

In this Letter, we present a compact scattering spectrometer system based on fluorosilicate glass ceramics. By the algorithmic spectral calibration and reconstruction, we achieve wavelength detection with a resolution of 0.1 nm. Numerous nanocrystals embedded in the glass host in the glass ceramics result in a significant natural multilayer scattering medium, which can provide a 60% scattering efficiency for incident light while increasing the optical path of incident light transmitting in the medium. The glass ceramics scattering medium with a rather compact physical size is integrated with a low-cost camera to compose an optical spectral system, which has potential application in lab-on-a-chip optical spectroscopy.

Thermal bleaching of BACs in bismuth/erbium co-doped fiber fabricated through 3D silica lithography.

Bismuth/erbium co-doped optical fiber fabricated through 3D silica lithography is thermally treated with various conditions. Then the thermal treatment effect on bismuth active centers (BACs) in this fiber is investigated. The thermal bleaching of the BAC associated with Al and the BAC associated with Si is observed after thermal treatment at high temperatures (300°C-800°C). It is found that the absorption and luminescence of BACs dramatically decrease after the thermal treatment, even totally bleaching at 700°C. The results show that the temperature and dwell time have significant effects on the thermal bleaching and activation of BACs. The underlying mechanisms of these thermal-induced effects are further discussed.

Silica optical fiber drawn from 3D printed preforms.

Silica optical fiber was drawn from a three-dimensional printed preform. Both single mode and multimode fibers are reported. The results demonstrate additive manufacturing of glass optical fibers and its potential to disrupt traditional optical fiber fabrication. It opens up fiber designs for novel applications hitherto not possible.

Thermally aggravated photo-bleaching of BAC-Al in bismuth/erbium co-doped optical fiber.

The thermal effect upon the photo-bleaching of bismuth/erbium co-doped optical fiber (BEDF) containing Al has been investigated. The photo-bleaching effects of aluminum related bismuth active center (BAC-Al) in BEDF are studied from room temperature (RT) up to 350°C under the irradiation of a 980 nm laser. No visible bleaching of the luminescence associated with BAC-Al was observed at RT, but significant bleaching appeared at higher temperatures above 150°C under the same irradiation power. The underlying mechanism of significant thermal aggravation of photo-bleaching is discussed, and its impact needs to be considered in the design and application of optical amplifiers and lasers using Al-doped BEDF.

BAC activation by thermal quenching in bismuth/erbium codoped fiber.

We have investigated the thermal quenching effect on the bismuth active center (BAC) in a Bi/Er co-doped fiber (BEDF). The effects from varying quenching conditions are studied and discussed. We report, for the first time to our knowledge, a significant BAC activation achieved by thermal quenching. We observed that the peak luminescence at ∼1405 nm of the BAC associated with silica (BAC-Si) could be enhanced more than two times by thermal quenching. The experimental results indicate that thermal quenching could be an effective way for BAC activation of bismuth-doped fibers.

Broadband multicolor upconversion from Yb3+-Mn2+ codoped fluorosilicate glasses and transparent glass ceramics.

In contrast to well-known upconversion (UC) emission from Yb3+-Mn2+-codoped crystal, a room-temperature intense broadband UC phenomenon was first observed in both Yb3+-Mn2+-codoped fluorosilicate glasses and transparent glass ceramics under 980 nm pumping. The obtained photoluminescence ranged from yellow to white to blue. We attributed this effect to the cooperative UC of Yb3+ and to the formation of Yb3+-Mn2+ pairs. After heat treatment, KZnF3 nanocrystals appeared in the glass matrix, as identified by x-ray diffraction and transmission electron microscopy, and emission intensity increased 45 times. We believe that Yb3+-Mn2+-codoped glasses and glass ceramics show great potential as materials for multicolor displays.

Ce(3+)/Yb(3+)/Er(3+) triply doped bismuth borosilicate glass: a potential fiber material for broadband near-infrared fiber amplifiers.

Erbium doped bismuth borosilicate (BBS) glasses, possessing the broadest 1.55 µm near infrared (NIR) emission band among oxide glasses, stand out as excellent fiber material for optical fiber amplifiers. In this work, we demonstrate that both broadened and enhanced NIR emission of Er(3+) can be obtained by sensibly combining the effects such as mixed glass former effect, phonon-assisted energy transfer (PAET) and de-excitation effect induced by codopant. Specially, by codoping CeO2 in a controlled manner, it leads to not only much improved optical quality of the glasses, enhanced NIR emission, but also significantly suppressed energy transfer up-conversion (ETU) luminescence which is detrimental to the NIR emission. Cerium incorporated in the glasses exists overwhelmingly as the trivalent oxidation state Ce(3+) and its effects on the luminescence properties of Er(3+) are discussed. Judd-Ofelt analysis is used to evaluate gain amplification of the glasses. The result indicates that Ce(3+)/Yb(3+)/Er(3+) triply doped BBS glasses are promising candidate for erbium doped fiber amplifiers. The strategy described here can be readily extended to other rare-earth ions (REs) to improve the performance of REs doped fiber lasers and amplifiers.