Abstract A highly sensitive photodeflection spectroscopy technique with femtosecond time resolution has been developed. Using this technique, we have measured accurately the shape of acoustic pulses, which were generated from the ultrafast phonon emission in a germanium plate. Supersonic expansion of photoexcited electron-hole plasma was observed. The characteristic velocity of plasma diffusion was evaluated. It exceeded the longitudinal sound velocity in germanium by a factor of 4.0.
Received: 27 April 2004
Revised: 01 September 2004
Accepted manuscript online:
Fund: Project supported by the State Key Basic Research Special Foundation of China (Grant No TG1999075209), the National Natural Science Foundation of China ( Grant Nos 90206003,60378012, 10328407 and 90101027). The project was also supported by the Scientific
Cite this article:
Pan Xin-Yu (潘新宇), Chigarev N. V., Gong Qi-Huang (龚旗煌) Femtosecond photodeflection spectroscopy in thin monocrystalline plates of germanium 2005 Chinese Physics 14 212
Altmetric calculates a score based on the online attention an article receives. Each coloured thread in the circle represents a different type of online attention. The number in the centre is the Altmetric score. Social media and mainstream news media are the main sources that calculate the score. Reference managers such as Mendeley are also tracked but do not contribute to the score. Older articles often score higher because they have had more time to get noticed. To account for this, Altmetric has included the context data for other articles of a similar age.