Electrical delay technique in the picosecond thermoreflectance method for thermophysical property measurements of thin films
Electrical delay technique in the picosecond thermoreflectance method for thermophysical property measurements of thin films
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DOI：
10.1063/1.2038628
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发表时间：
2005-09
影响因子：
1.6
通讯作者：
N. Taketoshi;T. Baba;A. Ono
中科院分区：
文献类型：
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作者：
N. Taketoshi;T. Baba;A. Ono
为了延长脉冲加热后薄膜温度响应的观测时间，研制了一种新的皮秒热反射测量系统。新系统使用两个皮秒钛蓝宝石激光器，一个用于加热样品，另一个用于探测薄膜表面的温度变化。通过改变探测光相对于泵浦光的延迟时间，而不是改变泵浦光与探测光之间的光程差，观察到了薄膜表面的温度历程。利用电延迟技术，在比皮秒激光脉冲的重复周期更长的时间内观察温度历史并不困难。电延迟技术可以消除光束通过变光程延迟线后在样品表面聚焦位置的波动。溅射钨薄膜的温度历史曲线。
A new picosecond thermoreflectance measurement system using an electrical delay control has been developed in order to extend observation time of temperature response of thin films after pulse heating. The new system uses two picosecond titanium sapphire lasers, one for heating a specimen and the other for probing temperature change on the film surface. Temperature history of the film surface is observed by changing the delay time of the probe pulse from the pump pulse electrically instead of changing the difference of path length between the pump beam and the probe beam. It is not difficult to observe temperature history over longer time than the repetition period of the picosecond laser pulses using the electrical delay technique. The electrical delay technique can get rid of the fluctuation of focused position of the beam on the specimen surface which is hard to eliminate after traveling through the optical delay line of variable path length. Temperature history curves of sputtered tungsten thin films ...