We analyzed the SRY data obtained in klog:37440. The deviation from the design value was 2.168(80) cm when the HWP scale was 14 and the polarizer scale was 295, and 2.319(71) cm when the HWP scale was 59 and the polarizer scale was 250. Compared with the previous measurement (klog:37393), which gave a deviation of 2.385(42) cm from the SRY design value, the result with the HWP scale at 59 is consistent, while the result with the HWP scale at 14 appears to be slightly different. Both results differ more significantly from the result before moving the lens to improve the mode-matching ratio (klog:37250), which gave a deviation of 1.757(50) cm from the design value.

Using the SRX result from klog:37450, we also calculated the SRC length and the Schnupp asymmetry. The SRC lengths were 66.61778(45) m for the HWP scale of 14 and polarizer scale of 295, and 66.61853(41) m for the HWP scale of 59 and polarizer scale of 250. The Schnupp asymmetries calculated from the SRC lengths were 3.339390(904) m and 3.337880(825) m, respectively. Compared with the previous measurement (klog:37393), which gave an SRC length of 66.61828(92) m and a Schnupp asymmetry calculated from the SRC of 3.33605(185) m, both SRC lengths are consistent, while the Schnupp asymmetry with the HWP scale at 14 appears to be slightly different. Compared with the results before moving the lens to improve the mode-matching ratio (klog:37260), which gave an SRC length of 66.61409(70) m and a Schnupp asymmetry calculated from the SRC of 3.34023(139) m, both SRC lengths are slightly different, while the Schnupp asymmetry with the HWP scale at 59 appears to be slightly different.
 

• We fitted the SRY data obtained in klog:37440 with and without a linear background. I will post the fitting results for the individual peaks later. From the peak frequencies obtained from the fits and their uncertainties, we calculated the minimum and maximum values within the uncertainty ranges. We then took the overall minimum and maximum values from both fitting models, with and without a linear background, as the uncertainty range. The following data were therefore used to determine the SRY length.

  HWP scale: 14, Polarizer scale: 295
  Minimum (MHz)    Maximum (MHz)
  1611.7206    1611.8190
  810.9479    811.0371
  -846.1329    -845.9886
  -1656.2458    -1656.2199

  HWP scale: 59, Polarizer scale: 250
  Minimum (MHz)    Maximum (MHz)
  1599.4960    1599.5586
  789.4376    789.4956
  -814.5555    -814.4679
  -1583.0683    -1583.0217

  We set the FSR index of the data around -1.6 GHz to 0. For each pair of nearby peak frequencies, we calculated the frequency difference and divided it by the design value of the FSR. We then rounded the resulting value to the nearest integer to determine the FSR index. We fitted the measured peak frequencies as a function of the FSR index using the linear function AN+B, where A and B are fitting parameters and N is the FSR index.

  The fitting results were as follows.

  HWP scale: 14, Polarizer scale: 295 (Fig. 1)
  A: 2.307939(29) MHz
  B: -1656.230(13) MHz
  HWP scale: 59, Polarizer scale: 250 (Fig. 2)
  A: 2.307886(26) MHz
  B: -1583.043(22) MHz

  Since A corresponds to the FSR, we calculated the SRY length from the fitted value of A. The results were as follows.

  HWP scale: 14, Polarizer scale: 295
  Fitted length: 64.94808(80) m
  Design value: 64.9264 m
  Difference from the design value (fitted length − design value): 2.168(80) cm
  HWP scale: 59, Polarizer scale: 250
  Fitted length: 64.94959(71) m
  Design value: 64.9264 m
  Difference from the design value (fitted length − design value): 2.319(71) cm

  Compared with the previous measurement (klog:37393), which gave a deviation of 2.385(42) cm from the SRY design value, the result with the HWP scale at 59 is consistent, while the result with the HWP scale at 14 appears to be slightly different. Both results differ more significantly from the result before moving the lens to improve the mode-matching ratio (klog:37250), which gave a deviation of 1.757(50) cm from the design value.
   

• Using the SRX result from klog:37450, we calculated the SRC length and the Schnupp asymmetry as follows.

  HWP scale: 14, Polarizer scale: 295
  SRC
  Calculated value: 66.61778(45) m
  Design value: 66.5913 m
  Difference from the design value (calculated value − design value): 2.648(45) cm

  Schnupp asymmetry calculated from the SRC
  Calculated value: 3.339390(904) m
  Design value: 3.3298 m
  Difference from the design value (calculated value − design value): 0.9590(904) cm

  HWP scale: 59, Polarizer scale: 250
  SRC
  Calculated value: 66.61853(41) m
  Design value: 66.5913 m
  Difference from the design value (calculated value − design value): 2.723(41) cm

  Schnupp asymmetry calculated from the SRC
  Calculated value: 3.337880(825) m
  Design value: 3.3298 m
  Difference from the design value (calculated value − design value): 0.8080(825) cm

  Compared with the previous measurement (klog:37393), which gave an SRC length of 66.61828(92) m and a Schnupp asymmetry calculated from the SRC of 3.33605(185) m, both SRC lengths are consistent, while the Schnupp asymmetry with the HWP scale at 14 appears to be slightly different. Compared with the results before moving the lens to improve the mode-matching ratio (klog:37260), which gave an SRC length of 66.61409(70) m and a Schnupp asymmetry calculated from the SRC of 3.34023(139) m, both SRC lengths are slightly different, while the Schnupp asymmetry with the HWP scale at 59 appears to be slightly different.