Broadband Absorption Properties Research Articles

Graphene Oxide-Polythiophene Hybrid with Broad-Band Absorption and Photocatalytic Properties.

Hybrid graphene oxide (GO)/poly(3-hexylthiophene-2,5-diyl) (P3HT) sheets are assembled via π-π interaction and carefully isolated from the nonreacted precursors. The mutual influence of the two phases can be sharply manifested in this layer-to-layer configuration because it is undiluted by excess of one phase. To investigate the optical properties of the hybrid and possible synergistic interactions, we applied photothermal deflection spectroscopy (PDS) and pump-probe techniques. For the first time, the photocatalytic performance of these hybrids was investigated to correlate with their optical properties. The GO-P3HT hybrid demonstrates broad-band absorption and ultrafast charge transfer (1.4 ps) and acts as an excellent photocatalyst for the Mannich reaction (93% yield).

Spectroscopic and Laser Properties of the Near-Infrared Tunable Laser Material Yb3+-Doped CaF2 Crystal

High-quality oxygen-free 5 mol %Yb3+-doped CaF2 single crystal grown by the Czochralski method has been studied for its broadband absorption and emission properties. We present its spectroscopy at room and low temperatures and laser operation will be demonstrated around 1.05 µm with a slope efficiency of 57% with various transmission output couplers. The laser wavelength could be tuned between 1030 and 1070 nm.

Tm3+:CaF2 for 1.9 $mu;m laser operation

Tm3+ doped CaF2 single crystals have been grown and studied for their broadband absorption and emission properties. Tunable laser operation was demonstrated for the first time around 1.9 μm. Their spectroscopic investigation shows that rare-earth ions interactions occur at relatively low dopant concentrations, thus favoring 1.9 μm emission, more particularly. As a matter of fact, efficient, tunable, room temperature laser operation is reported around 1.9 μm with a 1.34% Tm3+ doped sample. The crystal was pumped at about 767 nm and the emission wavelength was tuned between 1835 and 1970 nm. A slope efficiency of 41% is achieved with a 10% transmission output coupler.

Tm 3+:CaF 2 for 1.9 μm laser operation

Tm 3+ doped CaF 2 single crystals have been grown and studied for their broadband absorption and emission properties. Tunable laser operation was demonstrated for the first time around 1.9 μm. Their spectroscopic investigation shows that rare-earth ions interactions occur at relatively low dopant concentrations, thus favoring 1.9 μm emission, more particularly. As a matter of fact, efficient, tunable, room temperature laser operation is reported around 1.9 μm with a 1.34% Tm 3+ doped sample. The crystal was pumped at about 767 nm and the emission wavelength was tuned between 1835 and 1970 nm. A slope efficiency of 41% is achieved with a 10% transmission output coupler.