Archives of Peking University News - PKU English - 北京大学

More documents

Recommendations

Info

北京大学英语新闻网/Peking University News Picosecond and Low-power All-optical Switching Based on Organic Photonicbandgap Microcavity Reported by PKU Researchers hailed as Breakthrough in Mesoscopic Physics PKU NEWS 2008--02—25 http://ennews.pku.edu.cn/news.php?s=203915529 Peking University, Feb. 25, 2008: A research group led by Professor Gong Qihuang from State Key Laboratory for Mesoscopic Physics, Department of Physics of Peking University has devised a strategy for making ultrafast photonic-crystal-based optical switches that can operate under low-power pump light. Their research paper will soon be published on Nature Photonics. This paper has been published online on Feb. 3 [Xiaoyong Hu, Ping Jiang, Chengyuan Ding, Hong Yang and Qihuang Gong*,Picosecond and low-power all-optical switching based on an organic photonic-bandgap microcavity. Nature Photonics, advance online publication, 03 February 2008 (doi: 10.1038/nphoton.2007.299)]. News titled ―Photonic crystals speed up all-optical switching‖ was released on Optics.org and Nature China highlighted this scientific achievement as "Optical switches: A new low". Most photonic crystals require high pump powers to operate because they have low nonlinearity — that is, there is little interaction between the pump light and the crystal. For crystals with high nonlinearity, the response time of optical switching can become problematically slow. The researchers formed a rectangular photonic crystal (pictured top) by connecting 20 slabs together. Each slab, etched with periodic patterns of submicrometre holes, is made from a blend of polymer and organic chromophore, which have absorption bands that overlap each other. A line defect (pictured bottom) was allocated at the centre of the crystal to create a ‗microcavity‘, or quantum confinement well, which enhances the interaction between the pump light and the crystal. When pump light at a frequency within the absorption band was used to excite the crystal, the nonlinearity properties were enhanced by two orders of magnitude as a result of the microcavity. A pump power of 110 kW cm 2 is needed for the crystal to 320
北京大学英语新闻网/Peking University News perform optical switching — about four orders of magnitude less than that of previous reports. The response time need not be compromised because the interelectron transfer between the polymer and the chromophore is fast, enabling response times of 1.2 picoseconds. This new report provides a strategy for constructing photonic materials with large nonlinearity and studying ultrafast low-power integrated photonic devices. This scientific program is supported by Science Fund for Creative Research Groups from National Science Foundation of China (NSFC) and National Basic Research Program of China. Sources: http://www.nature.com/nphoton/journal/vaop/ncurrent/pdf/nphoton.2007.299.pdf http://www.nature.com/nchina/2008/080220/full/nchina.2008.39.html http://optics.org/cws/article/research/32975 Edited By : Wang Yi Translated By : Wang Yi Related Topic : Related News : Related Feedback : 321
Page 1:
北京大学英语新闻存档(第
Page 4 and 5:
指导教师刘乃勇本卷编辑
Page 6 and 7:
北京大学英语新闻网/Peking
Page 8 and 9:
Page 10 and 11:
Page 12 and 13:
Page 14 and 15:
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
Page 204 and 205:
Page 206 and 207:
Page 208 and 209:
Page 210 and 211:
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Page 218 and 219:
Page 220 and 221:
Page 222 and 223:
Page 224 and 225:
Page 226 and 227:
Page 228 and 229:
Page 230 and 231:
Page 232 and 233:
Page 234 and 235:
Page 236 and 237:
Page 238 and 239:
Page 240 and 241:
Page 242 and 243:
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Page 268 and 269:
Page 270 and 271:
Page 272 and 273:
Page 274 and 275:
Page 276 and 277:
Page 278 and 279:
Page 280 and 281:
Page 282 and 283:
Page 284 and 285:
Page 286 and 287:
Page 288 and 289:
Page 290 and 291:
Page 292 and 293:
Page 294 and 295:
Page 296 and 297:
Page 298 and 299:
Page 300 and 301: 北京大学英语新闻网/Peking
Page 400 and 401:
Page 402 and 403:
Page 404 and 405:
Page 406 and 407:
Page 408 and 409:
Page 410 and 411:
Page 412 and 413:
Page 414 and 415:
Page 416 and 417:
Page 418 and 419:
Page 420 and 421:
Page 422 and 423:
Page 424 and 425:
Page 426 and 427:
Page 428 and 429:
Page 430 and 431:
Page 432 and 433:
Page 434 and 435:
Page 436 and 437:
Page 438 and 439:
Page 440 and 441:
Page 442 and 443:
Page 444 and 445:
Page 446 and 447:
Page 448 and 449:
Page 450 and 451:
Page 452 and 453:
Page 454 and 455:
Page 456 and 457:
Page 458 and 459:
Page 460 and 461:
Page 462 and 463:
Page 464 and 465:
Page 466 and 467:
Page 468 and 469:
Page 470 and 471:
Page 472 and 473:
Page 474 and 475:
Page 476 and 477:
Page 478 and 479:
Page 480 and 481:
Page 482 and 483:
Page 484 and 485:
Page 486 and 487:
Page 488 and 489:
Page 490 and 491:
Page 492 and 493:
Page 494 and 495:
Page 496 and 497:
Page 498 and 499:
Page 500 and 501:
Page 502 and 503:
Page 504 and 505:
Page 506 and 507:
Page 508 and 509:
Page 510 and 511:
Page 512 and 513:
Page 514 and 515:
Page 516 and 517:
Page 518 and 519:
Page 520 and 521:
Page 522 and 523:
Page 524 and 525:
Page 526 and 527:
Page 528 and 529:
Page 530 and 531:
Page 532 and 533:
Page 534 and 535:
Page 536 and 537:
Page 538 and 539:
Page 540 and 541:
Page 542 and 543:
Page 544 and 545:
Page 546 and 547:
Page 548 and 549:
Page 550 and 551:
Page 552 and 553:
Page 554 and 555:
Page 556 and 557:
Page 558 and 559:
Page 560 and 561:
Page 562 and 563:
Page 564 and 565:
Page 566 and 567:
Page 568 and 569:
Page 570 and 571:
Page 572 and 573:
Page 574 and 575:
Page 576 and 577:
Page 578 and 579:
Page 580 and 581:
Page 582 and 583:
Page 584 and 585:
Page 586 and 587:
Page 588 and 589:
Page 590 and 591:
Page 592 and 593:
Page 594 and 595:
Page 596 and 597:
Page 598 and 599:
Page 600 and 601:
Page 602 and 603:
Page 604 and 605:
Page 606 and 607:
Page 608 and 609:
Page 610 and 611:
Page 612 and 613:
Page 614 and 615:
Page 616 and 617:
Page 618 and 619:
Page 620 and 621:
Page 622 and 623:
Page 624 and 625:
Page 626 and 627:
Page 628 and 629:
Page 630 and 631:
Page 632 and 633:
Page 634 and 635:
Page 636 and 637:
Page 638 and 639:
Page 640 and 641:
Page 642 and 643:
Page 644 and 645:
Page 646 and 647:
Page 648 and 649:
Page 650 and 651:
Page 652 and 653:
Page 654 and 655:
Page 656 and 657:
Page 658 and 659:
Page 660 and 661:
Page 662 and 663:
Page 664 and 665:
Page 666 and 667:
Page 668 and 669:
Page 670 and 671:
Page 672 and 673:
Page 674 and 675:
Page 676 and 677:
Page 678 and 679:
Page 680 and 681:
Page 682 and 683:
Page 684 and 685:
Page 686 and 687:
Page 688 and 689:
Page 690 and 691:
Page 692 and 693:
Page 694 and 695:
Page 696 and 697:
Page 698 and 699:
Page 700 and 701:
Page 702 and 703:
Page 704 and 705:
Page 706 and 707:
Page 708 and 709:
Page 710 and 711:
Page 712 and 713:
Page 714 and 715:
Page 716 and 717:
Page 718 and 719:
Page 720 and 721:
Page 722 and 723:
Page 724 and 725:
Page 726 and 727:
Page 728 and 729:
Page 730 and 731:
Page 732 and 733:
Page 734 and 735:
Page 736 and 737:
Page 738 and 739:
Page 740 and 741:
Page 742 and 743:
Page 744 and 745:
Page 746 and 747:
Page 748 and 749:
Page 750 and 751:
Page 752 and 753:
Page 754 and 755:
Page 756 and 757:
Page 758 and 759:
Page 760 and 761:
Page 762 and 763:
Page 764 and 765:
Page 766 and 767:
Page 768 and 769:
Page 770 and 771:
Page 772 and 773:
Page 774 and 775:
Page 776 and 777:
Page 778 and 779:
Page 780 and 781:
Page 782 and 783:
Page 784 and 785:
Page 786 and 787:
Page 788 and 789:
Page 790 and 791:
Page 792 and 793:
Page 794 and 795:
Page 796 and 797:
Page 798 and 799:
Page 800 and 801:
Page 802 and 803:
Page 804 and 805:
Page 806 and 807:
Page 808 and 809:
Page 810 and 811:
Page 812 and 813:
Page 814 and 815:
Page 816 and 817:
Page 818 and 819:
Page 820 and 821:
Page 822 and 823:
Page 824 and 825:
Page 826 and 827:
Page 828 and 829:
Page 830 and 831:
Page 832 and 833:
Page 834 and 835:
Page 836 and 837:
Page 838 and 839:
Page 840 and 841:
Page 842 and 843:
Page 844 and 845:
Page 846 and 847:
Page 848 and 849:
Page 850 and 851:
Page 852 and 853:
Page 854 and 855:
Page 856 and 857:
Page 858 and 859:
Page 860 and 861:
Page 862 and 863:
Page 864 and 865:
Page 866 and 867:
Page 868 and 869:
Page 870 and 871:
Page 872 and 873:
Page 874 and 875:
Page 876 and 877:
Page 878 and 879:
Page 880 and 881:
Page 882 and 883:
Page 884 and 885:
Page 886 and 887:
Page 888 and 889:
Page 890 and 891:
Page 892 and 893:
Page 894 and 895:
Page 896 and 897:
Page 898 and 899:
Page 900 and 901:
Page 902 and 903:
Page 904 and 905:
Page 906 and 907:
Page 908 and 909:
Page 910 and 911:
Page 912 and 913:
Page 914 and 915:
Page 916 and 917:
Page 918 and 919:
Page 920 and 921:
Page 922 and 923:
Page 924 and 925:
Page 926 and 927:
Page 928 and 929:
Page 930 and 931:
Page 932 and 933:
Page 934 and 935:
Page 936 and 937:
Page 938 and 939:
Page 940 and 941:
Page 942 and 943:
Page 944 and 945:
Page 946 and 947:
Page 948 and 949:
Page 950 and 951:
Page 952 and 953:
Page 954 and 955:
Page 956 and 957:
Page 958 and 959:
Page 960 and 961:
Page 962 and 963:
Page 964 and 965:
Page 966 and 967:
Page 968 and 969:
Page 970 and 971:
Page 972 and 973:
Page 974 and 975:
Page 976 and 977:
Page 978 and 979:
Page 980 and 981:
Page 982 and 983:
Page 984 and 985:
Page 986 and 987:
Page 988 and 989:
Page 990 and 991:
Page 992 and 993:
Page 994 and 995:
Page 996 and 997:
Page 998 and 999:
Page 1000 and 1001:
Page 1002 and 1003:
Page 1004 and 1005:
Page 1006 and 1007:
Page 1008 and 1009:
Page 1010 and 1011:
Page 1012 and 1013:
Page 1014 and 1015:
Page 1016 and 1017:
Page 1018 and 1019:
Page 1020 and 1021:
Page 1022 and 1023:
Page 1024 and 1025:
Page 1026 and 1027:
Page 1028 and 1029:
Page 1030 and 1031:
Page 1032 and 1033:
Page 1034 and 1035:
Page 1036 and 1037:
Page 1038 and 1039:
Page 1040 and 1041:
Page 1042 and 1043:
Page 1044 and 1045:
Page 1046 and 1047:
Page 1048 and 1049:
Page 1050 and 1051:
Page 1052 and 1053:
Page 1054 and 1055:
Page 1056 and 1057:
Page 1058 and 1059:
Page 1060 and 1061:
Page 1062 and 1063:
Page 1064 and 1065:
Page 1066 and 1067:
Page 1068 and 1069:
Page 1070 and 1071:
Page 1072 and 1073:
Page 1074 and 1075:
Page 1076 and 1077:
Page 1078 and 1079:
Page 1080 and 1081:
Page 1082 and 1083:
Page 1084 and 1085:
Page 1086 and 1087:
Page 1088 and 1089:
Page 1090 and 1091:
Page 1092 and 1093:
Page 1094 and 1095:
Page 1096 and 1097:
Page 1098 and 1099:
Page 1100 and 1101:
Page 1102 and 1103:
Page 1104 and 1105:
Page 1106 and 1107:
Page 1108 and 1109:
Page 1110 and 1111:
Page 1112 and 1113:
Page 1114 and 1115:
Page 1116 and 1117:
Page 1118 and 1119:
Page 1120 and 1121:
Page 1122 and 1123:
Page 1124 and 1125:
Page 1126 and 1127:
Page 1128 and 1129:
Page 1130 and 1131:
Page 1132 and 1133:
Page 1134 and 1135:
Page 1136 and 1137:
Page 1138 and 1139:
Page 1140 and 1141:
Page 1142 and 1143:
Page 1144 and 1145:
Page 1146 and 1147:
Page 1148 and 1149:
Page 1150 and 1151:
Page 1152 and 1153:
Page 1154 and 1155:
Page 1156 and 1157:
Page 1158 and 1159:
Page 1160 and 1161:
Page 1162 and 1163:
Page 1164 and 1165:
Page 1166 and 1167:
Page 1168 and 1169:
Page 1170 and 1171:
Page 1172 and 1173:
Page 1174 and 1175:
Page 1176 and 1177:
Page 1178 and 1179:
Page 1180 and 1181:
Page 1182 and 1183:
Page 1184 and 1185:
Page 1186 and 1187:
Page 1188 and 1189:
Page 1190 and 1191:
Page 1192 and 1193:
Page 1194 and 1195:
Page 1196 and 1197:
Page 1198 and 1199:
Page 1200 and 1201:
Page 1202 and 1203:
Page 1204 and 1205:
Page 1206 and 1207:
Page 1208 and 1209:
Page 1210 and 1211:
Page 1212 and 1213:
Page 1214 and 1215:
Page 1216 and 1217:
Page 1218 and 1219:
Page 1220 and 1221:
Page 1222 and 1223:
Page 1224 and 1225:
Page 1226 and 1227:
Page 1228 and 1229:
Page 1230 and 1231:
Page 1232 and 1233:
Page 1234 and 1235:
Page 1236 and 1237:
Page 1238 and 1239:
Page 1240 and 1241:
Page 1242 and 1243:
Page 1244 and 1245:
Page 1246 and 1247:
Page 1248 and 1249:
Page 1250 and 1251:
Page 1252 and 1253:
Page 1254 and 1255:
Page 1256 and 1257:
Page 1258 and 1259:
Page 1260 and 1261:
Page 1262 and 1263:
Page 1264 and 1265:
Page 1266 and 1267:
Page 1268 and 1269:
Page 1270 and 1271:
Page 1272 and 1273:
Page 1274 and 1275:
Page 1276 and 1277:
Page 1278 and 1279:
Page 1280 and 1281:
Page 1282 and 1283:
Page 1284 and 1285:
Page 1286 and 1287:
Page 1288 and 1289:
Page 1290 and 1291:
Page 1292 and 1293:
Page 1294 and 1295:
Page 1296 and 1297:
Page 1298 and 1299:
Page 1300 and 1301:
Page 1302 and 1303:
Page 1304 and 1305:
Page 1306 and 1307:
Page 1308 and 1309:
Page 1310 and 1311:
Page 1312 and 1313:
Page 1314 and 1315:
Page 1316 and 1317:
Page 1318 and 1319:
Page 1320 and 1321:
Page 1322 and 1323:
Page 1324 and 1325:
Page 1326 and 1327:
Page 1328 and 1329:
Page 1330 and 1331:
Page 1332 and 1333:
Page 1334 and 1335:
Page 1336 and 1337:
Page 1338 and 1339:
Page 1340 and 1341:
Page 1342 and 1343:
Page 1344 and 1345:
Page 1346 and 1347:
Page 1348 and 1349:
Page 1350 and 1351:
Page 1352 and 1353:
Page 1354 and 1355:
Page 1356 and 1357:
Page 1358 and 1359:
Page 1360 and 1361:
Page 1362 and 1363:
Page 1364 and 1365:
Page 1366 and 1367:
Page 1368 and 1369:
Page 1370 and 1371:
Page 1372 and 1373:
Page 1374 and 1375:
Page 1376 and 1377:
Page 1378 and 1379:
Page 1380 and 1381:
Page 1382 and 1383:
Page 1384 and 1385:
Page 1386 and 1387:
Page 1388 and 1389:
Page 1390 and 1391:
Page 1392 and 1393:
Page 1394 and 1395:
Page 1396 and 1397:
Page 1398 and 1399:
Page 1400 and 1401:
Page 1402 and 1403:
Page 1404 and 1405:
Page 1406 and 1407:
Page 1408 and 1409:
Page 1410 and 1411:
Page 1412 and 1413:
Page 1414 and 1415:
Page 1416 and 1417:
Page 1418 and 1419:
Page 1420 and 1421:
Page 1422 and 1423:
Page 1424 and 1425:
Page 1426 and 1427:
Page 1428 and 1429:
Page 1430 and 1431:
Page 1432 and 1433:
Page 1434 and 1435:
Page 1436 and 1437:
Page 1438 and 1439:
show all

Archives of Peking University News - PKU English - 北京大学

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?