Doped Tellurite Glass Microsphere Research Articles

On-chip fabrication of air-bubble-containing Nd3+-doped tellurite glass microsphere for laser emission

We fabricated an air-bubble-containing glass microsphere on a substrate by using localized heating technique. Nd3+-doped tellurite glass cullets on a substrate were melted by a CW-Ti:sapphire laser at the wavelength of 810 nm and with the power density of more than 4.8 MW/cm2 to obtain tellurite glass microspheres with the diameter of 5 to 200 μm. The localized heating technique using laser is useful to form a bubble at a certain place in the microsphere. Both air-bubble-containing and bubble-free spheres showed lasing actions at around the wavelength of 1065 nm. The average laser thresholds of the air-bubble-containing and bubble-free microspheres with the size of 20-50 μm were 0.78 mW and 5.25 mW, respectively.

2 μ m lasing from highly thulium doped tellurite glass microsphere

A single mode microsphere laser at 2μm is demonstrated from a highly thulium doped tellurite glass microsphere. Glass samples with various doping concentrations are fabricated and characterized to choose the material with the highest pump efficiency. The laser wavelength is redshifted from the emission peak of thulium ions at 1800 nm due to the different mode distribution inside the microsphere. The laser line width (full width at half maximum) is measured as 115 MHz.

<inline-formula><math display="inline" overflow="scroll"><msup><mrow><mi>Er</mi></mrow><mrow><mn>3</mn><mo>+</mo></mrow></msup></math></inline-formula>-doped tellurite glass microsphere laser: optical properties, coupling scheme, and lasing characteristics

We present a comprehensive review of work on the Er3+-doped tellurite glass microsphere laser. We discuss the optical properties of Er3+-doped tellurite glass, including the emission cross section, the absorption cross section, and the lifetime analysis. Whispering-gallery modes in microspheres and fiber-taper coupling schemes are described, and theoretical analysis is performed for optimization. Finally, lasing characteristics such as the threshold, the lasing wavelength, and the temperature dependence of the microsphere laser are analyzed. Microsphere lasers with different Er2O3 doping concentrations have been fabricated and examined. A state-of-the-art L-band microsphere laser with 124.5-µW maximum output power is demonstrated. These miniature microsphere lasers have great potential and have attracted considerable attention because of their versatility for signal processing, fiber communication, and photon computation, as well as laser stabilization and sensing applications.

S -band Tm3+-doped tellurite glass microsphere laser via a cascade process

We present a Tm3+-doped tellurite glass microsphere laser operating in the S band via a cascade process. The microsphere is fabricated by melting the end of a tellurite glass wire, and the microsphere laser is pumped at 800nm using a tapered optical fiber. Laser oscillation is observed simultaneously in the S band and the 1.9μm band. The threshold of lasing in the 1.9μm band is lower than in the S band, and the quantum efficiency in the 1.9μm band increases with pump power above the lasing threshold of the S band.

Temperature dependence of the wavelength and threshold of fiber-taper-coupled L-band Er3+-doped tellurite glass microsphere laser

We report on the temperature dependence of L-band laser emission of fiber-taper-coupled Er3+-doped tellurite glass microsphere. The microsphere laser emission threshold increased and the emitted laser wavelength shifted with temperature. The experimental results are explained with a quasi-four-level model, showing that a significant reduction of laser threshold can be achieved at lower temperatures and higher Q values of this microsphere laser.

Fiber-taper-coupled L-band Er3+-doped tellurite glass microsphere laser

Er 3+ -doped tellurite glass microspheres were fabricated. The microspheres were made by a spin method. A tapered fiber was used to couple the pump into the microsphere and couple out the laser. L-band microsphere laser is demonstrated. This miniature Er3+-doped tellurite glass microsphere laser can be used in photonic microdevices.