Higase Youtaro, Morita Shinya, Fujii Toshiyuki, Takahashi Shun, Yamashita Kenichi, Sasaki Fumio
Opt Lett. 2018 Apr 15;43(8):1714-1717. doi: 10.1364/OL.43.001714.
We investigated optical gain and lasing characteristics of a polymer thin film co-doped with Rhodamine 6G and 4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran dye molecules. By the co-doping of these dyes, the optical gain coefficient and its spectral range were enhanced and widened, respectively. These results cannot be accounted for by the linear combination of the optical gain properties of single-doped films. Owing to this high-gain and wide-band optical amplification property, a distributed feedback lasing with a low threshold of 70 μJ/cm as well as a widely tunable wavelength range of 587-613 nm was achieved. We attribute this amplification property of the co-doped film, which cannot be achieved with the single-doped films, to the appearance of a coupled excited state between the two molecules.
我们研究了共掺杂若丹明6G和4-（二氰基亚甲基）-2-甲基-6-（4-二甲基氨基苯乙烯基）-4H-吡喃染料分子的聚合物薄膜的光学增益和激光特性。通过这些染料的共掺杂，光学增益系数及其光谱范围分别得到了增强和拓宽。这些结果无法用单掺杂薄膜光学增益特性的线性组合来解释。由于这种高增益和宽带光学放大特性，实现了阈值低至70 μJ/cm的分布反馈激光以及587 - 613 nm的宽可调谐波长范围。我们将这种共掺杂薄膜的放大特性（单掺杂薄膜无法实现）归因于两种分子之间出现的耦合激发态。
