中文摘要：

采用光抽运有机激光增益材料产生的放大自发辐射（amplified spontaneous emission ASE）,实现了不同浓度液体的实时检测.以两种聚合物poly（9,9-dioctylfluorene-co-benzothiadiazole）和poly（3-hexylthiophene）共混的激光增益介质薄膜作为平面光波导,观察在滴加少量溶液前后以及不同溶液浓度下,由于光波导的相对折射率变化导致的放大自发辐射阈值及峰位的变化,实现对溶液检测.实验结果显示,在常温常压下对25 wt.%NaCl溶液检测可得与纯水相比,放大自发辐射光谱红移了4.5 nm,ASE阈值从0.579μJ/pulse上升到1.447μJ/pulse,约2.5倍,溶液检测灵敏度达到97.8 nm/RIU（refractive index unit）,精度达到141.9 nm/RIU,充分说明上述方法能实现高灵敏度溶液检测。

英文摘要：

Laser has been widely applied in the scientific and engineering areas including communications, medical treatment,industry, and military due to its extremely strict monochromaticity, high coherence and high energy density. Organic laser based on solution processable polymer gain media has attracted considerable attention in various applications due to its easy fabrication, compact system and flexibility. At present, the chemosensors based on organic semiconductor laser have been widely developed. It has been reported to achieve solution monitoring by organic DFB（distributed feedback）laser. Although the method has its own advantages, there are still many operability and craftsmanship problems to be resolved. In this paper we introduce a new type of the real-time monitoring for various solution. The monitor is realized by using amplified spontaneous emission（ASE） from optically pumped organic semiconductor gain media.The gain media comprising blends of poly（9, 9-dioctylfluorene-co-benzothiadiazole）（F8BT） and poly（3-hexylthiophene）（P3HT） at a ratio of（15 ： 85） wt.% is dissolved into toluene（25 mg/m L）. Thin films（90 nm thickness） of P3HT/F8 BT are obtained by spin coating（2000 r/min） from solution onto pre-cleaned quartz substrates. The P3HT/F8 BT film demonstrates the absorption peak at 471 nm, the PL peak at 622 nm, and the ASE peak at 661 nm with FWHM（full-width-at-half-maximum） linewidth of -10 nm under the stripe laser pumping. The thin films are, then, covered by droplet of solution to form planar waveguide structure with variable effective refractive index. Upon analyte binding,a change in refractive index at the P3HT/F8 BT film surface results in a change in the effective refractive index of the planar waveguide and in turn induces shift of the ASE mode wavelength and variation of ASE threshold of the organic gain media. The changes in ASE wavelength and threshold can be monitored for sensing. The red shift of 4.5 nm in the ASE spectrum is from 661 to 665.5 nm an