Ike Y, Tsukada S, Kojima S
Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan.
Rev Sci Instrum. 2007 Jul;78(7):076104. doi: 10.1063/1.2753593.
Although the multichannel Brillouin spectroscopy with an angular dispersion-type Fabry-Perot interferometer (ADFPI) becomes a powerful tool for quick measurements, its resolution and contrast are not enough for the study of single crystals. A highly sensitive multichannel detector enables the ADFPI to use a solid etalon with high reflectivity (99.5%); hence, the high resolution and the high contrast of a spectrum are achieved. The finesse, the inverse of the resolution, reaches 100 with a 10 mm diameter of aperture size. The highest finesse of 140 is obtained by using a smaller diameter of 2 mm. The accuracy is examined by the measurement of a quartz crystal. The improvement in the resolution and contrast enables investigations of weak attenuation in a quartz crystal. The elastic anomaly of the alpha-beta transition of a quartz crystal is clearly observed both in sound velocity and attenuation. From the elastic constant c(11), the critical parameter K=0.76 is determined.
尽管采用角色散型法布里-珀罗干涉仪（ADFPI）的多通道布里渊光谱学成为快速测量的有力工具，但其分辨率和对比度对于单晶研究而言仍不够。高灵敏度多通道探测器使ADFPI能够使用具有高反射率（99.5%）的固体标准具；因此，可实现光谱的高分辨率和高对比度。精细度为分辨率的倒数，孔径尺寸为10毫米时达到100。通过使用2毫米的较小直径可获得最高140的精细度。通过对石英晶体的测量检验了精度。分辨率和对比度的提高使得能够研究石英晶体中的微弱衰减。在声速和衰减方面均清晰观察到石英晶体α-β转变的弹性异常。根据弹性常数c(11)，确定了临界参数K = 0.76。
