Ren T, Nuttall A L
J Acoust Soc Am. 2001 Feb;109(2):826-9. doi: 10.1121/1.1337957.
Measurement of the cochlear partition vibration as a function of the optical-axis (z-axis) position in the gerbil cochlea showed that the velocity distributes over a range of more than 300 microm, which is larger than the thickness of the cochlear partition. This finding suggests that the recording depth (RD) of the heterodyne interferometer probably is not as small as reported in the literature. In the current experiment, the RD of the heterodyne laser interferometer was studied by measuring the velocity of a vibrating mirror as a function of the z-axis position. Results demonstrate that the optical sectioning characteristic, measured by the intensity of the reflected laser beam as a function of the z-axis position, is not able to correctly estimate the RD of the heterodyne interferometer: the RD is much larger than optical sectioning, indicating a poor spatial resolution along the z axis.
对沙鼠耳蜗中蜗管振动随光轴（z轴）位置的测量表明，速度分布范围超过300微米，这比蜗管的厚度还要大。这一发现表明，外差干涉仪的记录深度（RD）可能不像文献中报道的那么小。在当前实验中，通过测量振动镜的速度随z轴位置的变化来研究外差激光干涉仪的RD。结果表明，通过反射激光束强度随z轴位置的变化来测量的光学切片特性，无法正确估计外差干涉仪的RD：RD比光学切片大得多，表明沿z轴的空间分辨率较差。
