Laser Diode Pumped Polymer Lasers with Tunable Emission Based on Microfluidic Channels

Tunable whispering-gallery-mode (WGM) lasers have been paid lots of attention for their potential applications in the photonic field. Here, a tunable polymer WGM laser based on laser diode pumping is realized with a threshold of 0.43 MW/cm2 per pulse. The WGM laser is realized by a microfluidic microcavity, which consists of a quartz capillary and gain materials. The laser performance keeps stable for a long time (3.5 h), pumped by a 50-ns 50 Hz laser diode with a pumping peak power density of 1.08 MW/cm2 per pulse. The lasing wavelength can be tuned over 15 nm by changing the gain material concentration from 3.5 mg/mL to 12.5 mg/mL in the microfluidic channel. Moreover, the lasing mode can be switched between transverse magnetic (TM) and transverse electric (TE) modes by adjusting the pump polarization. These results provide the basis for designing nanophotonic devices with laser diode pumping.

Crystal growth, structure and characterization of Er6B4O15as self-activated eye-safe laser material within the near-infrared waveband

A new rare-earth borate Er6B4O15was synthesized by a solid-state reaction technique. The crystal was obtained by a flux method. Single-crystal X-ray diffraction analysis revealed that the crystal structure is composed of ErO6polyhedra sharing edges and BO3groups. The absorption, near-infrared fluorescence spectra and the fluorescence decay curve of Er:4I13/2energy level in the Er6B4O15crystal were measured at room temperature. The absorption peak was located at 977 nm with absorption cross section of 1.16 × 10−21 cm2and a full width at half-maximum (FWHM) of 16 nm, which is very suitable for commercial 980 nm laser diode pumping. A maximum emission peak at 1560 mm with a broad FWHM of 64 nm was observed in this crystal because of the Er3+transition4I13/2→4I15/2, while the emission cross section was calculated to be 8.53 × 10−20 cm2. These results imply that the Er6B4O15crystal is a promising candidate material for the achievement of an eye-safe near-infrared wavelength laser.

Intense red up-conversion luminescence and dynamical processes observed in Sc2O3:Yb3+,Er3+ nanostructures

The intense red up-conversion luminescence in Sc2O3:Yb3+,Er3+ synthesized using a biphasic solvothermal (ST) method was observed upon laser diode pumping at 980 nm.