Micro-probing system of coherent phenomena in THz frequency region

由于半导体材料及其器件的研究，我们利用相干声子和光激发载流子的时间分辨研究，构建了太赫兹频段相干现象的微观探测表征系统。取得的研究成果如下：1.研究成果。双色泵浦-探测系统的试制我们在第一年就利用二次或三次谐波光构建了双色泵浦-探测系统。该系统的时间分辨率小于100fs2。微泵探头系统的试制。在物镜数值孔径为0.55，激光脉冲波长为810 nm的条件下，所构建的微泵-探测系统的分辨率约为2.7um*。这一结果与衍射极限下的计算分辨率基本一致。此外，使用微泵-探测系统的样品上的脉冲宽度小于100fs。这些结果表明，本文所构建的微泵-探测系统使我们能够研究相干声子和超晶格。利用微探测表征系统对半导体和超晶格中的相干声子及其波包和光激发载流子进行了时间分辨研究

We have constructed micro-probing characterization system of coherent system of coherent phenomena in THz frequency region because of investigations of semiconductor matenials and its devices by utilizing the time-resolved study of coherent phonons and photo-excited carriers. We obtain research results as follows1. Trial construction of two-color pump-probe system We have constructed two-color pump-probe system by using second or third harmonic generation light at the first year. The time resolution of this system is less than 100 fs2. Trial construction of micro-pump-probe system. The resolution of constructed micro-pump-probe system is about 2.7 um* under the condition that the numerical aperture of an objective lens used is 0.55 and the wavalength of the laser pulse is 810 nm. This result is almost consistent with the calculated resolution under the diffraction limit. Moreover, the pulse width on the sample using the micro-pump-probe system is less than 100 fs. These results demonstrate that the micro-pump-probe system constructed in the present work enable us to investigate the coherent phonon and superlattices3. Characterization of various sample by using a micro-probing characterization system We have performed the time-resolved study of the coherent phonons, their wave packet, and photo-excaited carriers in semiconductors and superlattices by using the micro-probing characterization system