# Subaru Telescope Infrared Secondary Mirror In-Situ Measured Reflectivity # Coated with Silver on 2019-11-07 # Opened the vacuum chamber on 2019-11-11 # Measured with Subaru Portable Spectrophotometer (SPS) on 2025-09-15 (2139 days after) # Measured three times # Data between 950 nm and 1650 nm are also available (SPS-XWW). # Contact: Hirofumi Okita (okita14@naoj.org) # # Wavelength (nm) #1 #2 #3 1000 99.38 99.08 98.00 998 99.34 99.35 98.13 996 99.17 99.48 99.36 994 99.29 99.51 98.62 992 98.74 98.80 99.42 990 98.84 99.38 99.68 988 99.22 99.78 99.48 986 97.89 99.58 98.99 984 98.44 99.19 98.31 982 99.33 100.33 98.83 980 98.95 98.84 99.40 978 98.73 98.46 99.53 976 99.22 99.11 99.47 974 98.43 99.64 98.89 972 98.50 99.77 99.32 970 98.53 99.39 98.41 968 99.36 99.29 99.13 966 99.52 98.93 98.74 964 98.58 99.58 98.25 962 98.08 99.23 98.39 960 99.59 99.32 99.02 958 99.00 99.04 99.02 956 98.66 98.85 99.07 954 98.83 99.22 98.99 952 98.94 98.67 99.41 950 98.77 99.22 99.43 948 98.46 98.99 98.99 946 99.05 99.08 98.70 944 98.58 99.23 98.92 942 99.03 98.06 98.68 940 99.89 99.75 98.92 938 98.80 99.01 99.45 936 99.17 98.85 98.85 934 98.89 99.15 98.63 932 98.67 99.00 99.02 930 98.70 99.04 99.19 928 99.18 99.09 99.26 926 98.72 99.00 99.37 924 98.65 99.39 99.47 922 99.70 99.09 99.51 920 98.90 99.09 98.79 918 98.62 98.96 99.08 916 98.64 99.02 99.19 914 99.04 99.30 99.30 912 98.81 99.32 98.13 910 98.70 99.26 99.13 908 99.20 99.30 98.87 906 99.57 98.97 98.59 904 99.02 98.86 98.94 902 99.21 99.23 99.03 900 98.96 99.65 98.64 898 98.92 98.76 99.45 896 99.07 99.31 98.90 894 99.08 99.15 99.11 892 98.76 99.18 99.07 890 99.05 98.83 98.72 888 98.95 99.06 99.06 886 99.50 99.21 98.74 884 99.02 98.99 99.32 882 98.61 98.93 98.91 880 99.27 99.18 98.90 878 98.78 99.14 99.45 876 99.03 99.29 98.96 874 99.22 99.19 98.86 872 98.90 99.20 98.93 870 99.16 99.04 98.60 868 98.43 99.19 99.05 866 99.06 98.90 98.61 864 98.97 99.00 98.98 862 98.90 98.75 98.90 860 98.67 99.09 98.78 858 99.26 99.17 99.03 856 98.61 98.98 98.73 854 99.04 98.93 98.95 852 99.12 99.09 98.77 850 98.63 99.16 98.55 848 98.59 98.95 98.93 846 98.60 99.22 98.88 844 98.93 99.16 98.59 842 98.76 98.94 98.74 840 98.65 99.25 98.73 838 98.81 99.18 98.48 836 98.82 99.31 98.45 834 98.40 99.57 98.62 832 98.73 98.89 98.61 830 99.03 99.43 99.30 828 98.49 99.01 98.77 826 98.94 98.85 98.55 824 98.58 98.41 98.51 822 98.60 99.01 98.97 820 98.92 99.21 98.43 818 98.85 98.84 98.76 816 98.52 98.92 98.71 814 98.78 98.65 98.89 812 98.66 98.77 98.23 810 98.40 98.94 98.61 808 98.66 99.04 98.63 806 98.62 99.10 98.44 804 98.74 98.97 98.64 802 98.62 98.74 98.49 800 98.75 98.68 98.85 798 98.88 99.01 98.83 796 98.53 98.93 98.65 794 98.47 98.47 98.58 792 98.56 99.02 98.55 790 98.52 98.36 98.27 788 98.37 98.59 98.47 786 98.41 98.79 98.42 784 98.62 98.96 98.60 782 98.60 98.82 98.48 780 98.61 98.70 98.06 778 98.39 98.86 98.57 776 98.50 98.89 98.45 774 98.29 98.57 98.39 772 98.31 98.71 98.65 770 98.36 98.90 98.08 768 98.35 98.60 98.42 766 98.47 98.63 98.14 764 98.36 98.56 98.66 762 98.70 98.34 98.31 760 98.39 98.70 98.19 758 98.02 98.74 98.56 756 98.37 98.61 98.23 754 98.25 98.67 98.04 752 98.09 98.14 98.36 750 98.45 98.31 98.17 748 98.36 98.72 97.99 746 98.12 98.39 98.36 744 98.17 98.42 98.07 742 98.47 98.52 98.13 740 98.27 98.26 98.40 738 98.16 98.25 98.29 736 98.18 98.39 97.95 734 98.09 98.58 97.93 732 97.96 98.67 98.14 730 98.15 98.55 98.22 728 97.99 98.34 98.19 726 97.93 98.42 98.01 724 98.11 98.29 97.91 722 98.10 98.33 98.34 720 98.22 98.22 97.87 718 98.08 98.37 97.91 716 98.06 97.94 98.15 714 97.96 98.23 98.12 712 97.89 98.31 98.05 710 98.05 98.37 97.84 708 98.10 98.08 98.06 706 97.81 98.33 97.90 704 97.92 98.05 97.78 702 97.92 98.12 97.87 700 97.76 98.08 97.93 698 97.62 97.97 98.02 696 97.89 98.21 97.84 694 97.70 97.88 97.64 692 97.76 98.09 97.59 690 97.76 98.27 97.72 688 97.82 98.14 97.74 686 97.83 97.99 97.61 684 97.66 97.83 97.80 682 97.66 97.72 97.44 680 97.70 97.92 97.71 678 97.66 97.78 97.69 676 97.70 97.85 97.67 674 97.80 98.07 97.75 672 97.42 97.76 97.59 670 97.47 97.60 97.37 668 97.59 98.00 97.54 666 97.49 97.80 97.38 664 97.45 97.65 97.34 662 97.47 97.65 97.27 660 97.37 97.72 97.53 658 97.20 97.64 97.23 656 97.34 97.37 97.40 654 97.38 97.64 97.30 652 97.14 97.52 97.48 650 96.94 97.35 96.98 648 97.02 97.41 96.86 646 97.19 97.21 96.88 644 96.92 97.18 97.03 642 96.88 97.05 96.95 640 96.95 97.15 96.86 638 96.85 97.22 97.19 636 96.87 97.07 96.80 634 96.72 97.25 96.87 632 97.11 97.19 96.77 630 96.88 96.99 96.80 628 96.54 97.03 96.67 626 96.58 97.18 96.58 624 96.70 97.00 96.60 622 96.76 96.94 96.80 620 96.66 96.97 96.73 618 96.50 97.17 96.35 616 96.72 97.00 96.55 614 96.52 96.66 96.55 612 96.54 96.92 96.63 610 96.40 96.74 96.41 608 96.41 96.80 96.47 606 96.45 96.71 96.43 604 96.50 96.77 96.30 602 96.39 96.56 96.11 600 96.30 96.74 96.31 598 96.41 96.76 96.20 596 96.09 96.59 96.24 594 96.22 96.44 96.10 592 96.14 96.38 96.15 590 96.06 96.68 95.98 588 96.22 96.53 95.96 586 96.12 96.31 95.72 584 95.85 96.09 96.17 582 95.86 96.31 95.95 580 95.69 96.23 95.92 578 95.83 96.20 95.75 576 95.67 96.15 95.67 574 95.49 96.00 95.57 572 95.45 95.96 95.48 570 95.48 95.79 95.27 568 95.37 95.78 95.21 566 95.37 95.57 95.52 564 95.20 95.70 95.24 562 95.30 95.67 95.26 560 95.34 95.36 95.36 558 95.32 95.60 94.93 556 94.92 95.12 95.19 554 95.03 95.21 94.76 552 94.88 95.34 94.84 550 94.72 95.13 94.72 548 94.63 95.10 94.58 546 94.71 94.87 94.49 544 94.64 94.80 94.31 542 94.37 94.64 94.62 540 94.30 94.69 94.22 538 94.20 94.33 94.00 536 94.03 94.28 93.85 534 94.06 94.41 93.87 532 93.95 94.21 93.71 530 93.91 94.08 93.43 528 93.34 93.95 93.66 526 93.31 93.96 93.46 524 93.42 93.78 93.28 522 93.12 93.33 93.15 520 93.20 93.60 92.93 518 93.09 93.53 92.67 516 92.71 93.45 92.50 514 92.77 93.12 92.38 512 92.33 93.03 92.45 510 92.09 92.76 92.31 508 92.07 92.65 92.27 506 91.94 92.40 91.98 504 91.71 92.06 91.56 502 91.66 91.93 91.70 500 91.51 91.87 91.52 498 91.31 91.65 91.19 496 90.92 91.65 91.07 494 90.87 91.20 90.65 492 90.56 90.94 90.56 490 90.47 91.13 90.12 488 89.90 90.49 90.15 486 89.88 90.28 90.06 484 89.59 90.02 89.59 482 89.48 89.87 89.19 480 89.13 89.55 89.08 478 89.00 89.56 88.74 476 88.83 88.90 88.59 474 88.26 88.71 88.46 472 87.92 88.37 88.08 470 87.77 88.44 87.77 468 87.81 87.78 87.40 466 87.34 87.52 87.16 464 86.92 87.36 87.01 462 87.13 86.94 86.77 460 86.13 86.58 86.49 458 85.81 86.57 86.03 456 85.80 86.14 85.39 454 85.21 85.67 85.30 452 85.22 85.40 85.13 450 84.77 85.46 84.98 448 84.54 85.00 84.62 446 84.13 84.46 84.12 444 83.68 84.44 84.05 442 83.12 84.18 83.80 440 82.83 83.73 83.05 438 82.79 83.11 82.53 436 82.65 82.94 82.23 434 82.25 82.46 82.05 432 81.65 81.87 82.01 430 81.54 81.40 81.04 428 80.87 80.93 80.93 426 80.14 80.95 80.02 424 79.75 80.00 79.85 422 79.37 79.51 79.55 420 78.75 79.11 78.84 418 78.91 78.50 77.97 416 77.56 77.45 77.63 414 76.78 76.81 77.12 412 76.25 77.35 76.61 410 75.29 76.38 76.02 408 75.26 75.76 75.51 406 74.50 74.96 74.12 404 73.39 74.66 73.67 402 73.38 73.69 73.05 400 72.27 72.62 72.49 398 72.14 72.05 72.27 396 69.57 72.81 72.47 394 70.19 71.21 70.76 392 69.27 70.17 69.89 390 68.92 69.14 69.18 388 68.70 69.04 68.72 386 68.17 67.73 68.76 384 66.97 67.57 68.19 382 66.90 66.85 67.95 380 66.56 65.89 67.07 1650 99.33 99.36 99.26 1640 99.32 99.38 99.26 1630 99.31 99.35 99.26 1620 99.29 99.36 99.27 1610 99.31 99.37 99.25 1600 99.29 99.36 99.26 1590 99.29 99.37 99.25 1580 99.28 99.36 99.26 1570 99.29 99.37 99.25 1560 99.28 99.36 99.25 1550 99.29 99.36 99.24 1540 99.28 99.36 99.24 1530 99.29 99.36 99.25 1520 99.27 99.35 99.25 1510 99.28 99.35 99.24 1500 99.28 99.35 99.24 1490 99.28 99.36 99.23 1480 99.27 99.34 99.23 1470 99.28 99.35 99.22 1460 99.28 99.33 99.22 1450 99.26 99.34 99.23 1440 99.27 99.34 99.22 1430 99.26 99.33 99.20 1420 99.26 99.33 99.21 1410 99.26 99.33 99.20 1400 99.26 99.32 99.20 1390 99.25 99.32 99.21 1380 99.26 99.33 99.20 1370 99.26 99.31 99.20 1360 99.25 99.31 99.19 1350 99.24 99.31 99.19 1340 99.24 99.30 99.19 1330 99.23 99.31 99.18 1320 99.22 99.30 99.18 1310 99.23 99.31 99.17 1300 99.22 99.30 99.17 1290 99.22 99.29 99.18 1280 99.22 99.29 99.17 1270 99.21 99.29 99.16 1260 99.21 99.29 99.17 1250 99.21 99.28 99.16 1240 99.21 99.28 99.16 1230 99.20 99.28 99.15 1220 99.20 99.28 99.15 1210 99.19 99.27 99.14 1200 99.18 99.28 99.15 1190 99.18 99.27 99.14 1180 99.19 99.26 99.14 1170 99.18 99.26 99.13 1160 99.16 99.25 99.11 1150 99.15 99.25 99.11 1140 99.16 99.25 99.11 1130 99.15 99.23 99.12 1120 99.14 99.25 99.10 1110 99.13 99.23 99.11 1100 99.13 99.23 99.08 1090 99.13 99.23 99.08 1080 99.11 99.22 99.07 1070 99.11 99.21 99.06 1060 99.11 99.20 99.05 1050 99.09 99.20 99.06 1040 99.09 99.18 99.05 1030 99.08 99.19 99.04 1020 99.06 99.18 99.02 1010 99.05 99.16 99.02 1000 99.05 99.16 99.02 990 99.04 99.15 98.98 980 99.04 99.14 98.99 970 99.02 99.13 98.97 960 99.01 99.13 98.96 950 99.02 99.11 98.97