Problems:There are some possibility that I mixed optical elements in different wavelength bands (1550nm and 1064nm) in ATC.
What I did: I checked the suspected optical elements used for 1550nm or not.
Subjects: Two HWP and one QWP that were suspected in 1064nm,but one HWP(named "1") is cleaned by using first contact. So I checked one HWP(named "2") and one QWP(named "3").
Experiments: I set up the following in attached pictures. In experiment for the suspected HWP(named "2"),maximum mW and mimimum mW showed in Power Meter was as follows.
| Maximum (mW) | Mimimum (mW) | |
| No ND filter | 11.64 | 0.02 |
| ND 0.2 filter | 8.84 | 0.01 |
| ND 1.0 filter | 1.59 | 0.01 |
In experiment for the suspected QWP(named "3"), maximum mW and mimimum mW showed in Power Meter was as follows.
| Maximum (mW) | Mimimum (mW) | |
| No ND filter | 3.51 | 0.07 |
| ND 0.2 filter | 2.67 | 0.06 |
| ND 1.0 filter | 0.48 | 0.01 |
Conclusion: Based on the above results, it can be concluded that HWP(named "2") and QWP(named "3") are for 1550nm wavelength.
Next: I will check the suspected HWP(named "1").
Addition: I checked WHP(named "1"),WHP(named "2"),and QWP(named "3")again.I set up the following in additional attached pictures.Additional experiments were set up the same as before.
In experiment for the suspected HWP(named "1"),maximum mW and mimimum mW showed in Power Meter was as follows.
| Maximum (mW) | Mimimum (μW) | |
| No ND filter | 11.65 | 8.47 |
| ND 0.2 filter | 8.972 | 6.57 |
| ND 1.0 filter | 1.679 | 1.19 |
In additional experiment for the suspected HWP(named "2"),maximum mW and mimimum mW showed in Power Meter was as follows.
| Maximum (mW) | Mimimum (μW) | |
| No ND filter | 11.59 | 8.40 |
| ND 0.2 filter | 9.039 | 6.48 |
| ND 1.0 filter | 1.762 | 1.23 |
In additional experiment for the suspected HWP(named "3"),mW showed in Power Meter at point A,B,and C was as follows.
| point A | point B | point C | |
| Power Meter(mW) | 12.14 | 3.693 | 3.826 |
Based on the above results, it was concluded that HWP(named "1"),HWP(named "2") and QWP(named "3") are for 1550nm wavelength.There was no mixing.
