Broadband 1.0†µm emission in Nd3+/Yb3+ co-doped phosphate glasses and fibers for photonic applications.

In this work, the spectroscopic properties of 1.0 µm emission in Nd3+/Yb3+ co-doped phosphate glasses were systematically investigated under 808 nm excitation. Notably, broadband 1.0 µm emission with a full width at half maximum (FWHM) of 96 nm was obtained in the phosphate glass doped with 2 mol.% Nd2O3 and 1 mol.% Yb2O3. In addition, the energy transfer microscopic parameter and transfer efficiency were analyzed. What is more, multimaterial fibers with Nd3+/Yb3+ co-doped phosphate glass core and silicate cladding were successfully drawn by using the molten core method. An intense 1.0 µm amplified spontaneous emission (ASE) can be realized in a 3 cm long multimaterial fiber. More importantly, the FWHM of the ASE can reach as large as 60 nm when excited at 976 nm. These results demonstrate that the Nd3+/Yb3+ co-doped phosphate glasses and fibers are promising gain materials for amplifier and laser applications in photonics.

Broadband near-infrared amplified spontaneous emission of Er3+-doped germanate glass fiber.

Er3+-doped glass and fiber are very attractive for near-infrared (NIR) lasers and photonic applications. In this work, the full width at half maximum (FWHM) of NIR fluorescence emission of the Er3+-doped germanate glass can be broadened from 72 to 99 nm when Al2O3 was added. In addition, the spectroscopic properties, including absorption and emission spectra, Judd-Ofelt intensity parameters, absorption and emission cross sections, gain coefficient, and fluorescence lifetime, of the Al2O3-modified germanate glass were systematically investigated. What is more, silicate-clad heavily Er3+-doped germanate core multimaterial fibers were successfully drawn by a rod-in-tube method. Notably, broadband NIR amplified spontaneous emission (ASE) with an FWHM of 120 nm was achieved in this new fiber. To the best of our knowledge, this is the largest FWHM reported for Er3+-doped germanate glass fibers. These results suggest that the as-drawn Er3+-doped germanate glass fiber with superior performances is a promising candidate for broadband optical amplification.

Efficient and Broadband Emission in Dy3+-Doped Glass-Ceramic Fibers for Tunable Yellow Fiber Laser.

Yellow lasers are of great interest in biology, medicine and display technology. However, nonlinear emission of near-infrared lasers at yellow still presents particularly complex optical alignment to date. Here, to the best of our knowledge, we demonstrate the fabrication of a NaLa(WO4)2: Dy3+ glass-ceramic fiber (GCF) for the first time. More importantly, the emission band of the GCF, which is around 575 nm, has a wide full-width half maximum (FWHM) of 18~22 nm, which is remarkably larger than that of the Dy3+-doped YAG crystal (<7 nm). The precursor fiber (PF) was drawn using the molten core drawing (MCD) method. In particular, benefiting from the in situ nanocrystals fabricated in the amorphous fiber core after thermal treatment, the resultant glass-ceramic fiber exhibits a five-times enhancement of luminescence intensity around 575 nm, compared with the precursor fiber, while retaining its broadband emission. Overall, this work is anticipated to offer a high potential GCF with prominent bandwidth for the direct access of a tunable yellow laser.