THORLABS OCT-LK Series, Руководство пользователя

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OCTP Series Scanner Chapter 4: Installation
Rev F, November 03, 2018 Page 21
 For OCTP:
To coarsely adjust the length of the reference arm, translate the mirror along the axis of the
30 mm cage system, either by loosening the top cage plate or the variable lens tube. Fine
adjustments of ±2 mm (total range of 4 mm) can be performed by tweaking the non-rotating
zoom housing, as shown in Figure 26. We recommend aligning the reference arm such that
when the sample is present, the non-rotating zoom housing is centered within its
adjustment range. In addition, if coarse adjustment of the reference arm length is
necessary, we recommend making the reference arm length slightly shorter than the
sample arm length.
 For OCTP-PS:
The coarse length adjustment is performed by changing the postion of the cage translation
stage. The fine adjustment of ±6 mm (total range of 12.7 mm) can be performed by using
the micrometer screw.
Figure 26 Fine Adjustment of Reference Arm Length OCTP (top) and OCTP-PS (bottom)
If no signal appears, check that the sample is at the focus of the objective and that the beam is not
blocked anywhere along its beam path. When using the IR card for adjustment, your B-scan image
should be similar to Figure 27.
Figure 27 OCT Image of IR Viewing Card
When not configured for a polarization-sensitive SD-OCT system, the alignment ends here.
Please continue below for adjusting the OCTP-PS.
4.3.2. Polarization Adjustment
In polarization-sensitive OCT, the polarization state of the incident light is adjusted in both the reference arm
and the sample arm. The incident light on the sample is circularly polarized light to achieve a sensitivity to all
polarization axes in the sample and to be independent on sample rotation in plane. In contrast, the light coming