Please wait a minute...
Frontiers of Physics

ISSN 2095-0462

ISSN 2095-0470(Online)

CN 11-5994/O4

邮发代号 80-965

2019 Impact Factor: 2.502

Front. Phys.   2010, Vol. 5 Issue (3): 266-276   https://doi.org/10.1007/s11467-010-0003-0
  Research articles 本期目录
Photonic crystals and microlasers fabricated with low refractive index material
Photonic crystals and microlasers fabricated with low refractive index material
Tian-rui ZHAI(翟天瑞),Da-he LIU(刘大禾),Xiang-dong ZHANG(张向东),
Department of Physics, Beijing Normal University, Beijing 100875, China;
 全文: PDF(504 KB)  
Abstract:Although the investigation on photonic band gap materials has been done more than two decades, it is still a big challenge to fabricate three-dimensional photonic crystal (PC) possessing wide band gaps in visible range. In this article, we have reviewed recent progresses on fabricating the PC with low refractive index material in visible range. In contrast to the material with large refractive index, it is cheap to use low refractive index material in fabricating the PC and will be greatly beneficial for future industrial productions. The holographic method to fabricate such a PC has been introduced, applying it to the design of the microlaser has also been discussed.
Key wordsphotonic crystal    low refractive index material    band gap    microlaser
出版日期: 2010-09-05
 引用本文:   
. Photonic crystals and microlasers fabricated with low refractive index material[J]. Front. Phys. , 2010, 5(3): 266-276.
Tian-rui ZHAI(翟天瑞), Da-he LIU(刘大禾), Xiang-dong ZHANG(张向东), . Photonic crystals and microlasers fabricated with low refractive index material. Front. Phys. , 2010, 5(3): 266-276.
 链接本文:  
https://academic.hep.com.cn/fop/CN/10.1007/s11467-010-0003-0
https://academic.hep.com.cn/fop/CN/Y2010/V5/I3/266
E. Yablonovitch, Phys. Rev. Lett., 1987, 58: 2059

doi: 10.1103/PhysRevLett.58.2059
S. John, Phys. Rev. Lett., 1987, 58: 2486

doi: 10.1103/PhysRevLett.58.2486
J. D. Joannopoulos, R. D. Meade, and J. N. Winn, Photonic Crystals, Princeton: Princeton University Press, 1995
C. Soukoulis, Photonic Band Gap Materials, Norwell,MA: Kluwer, 1996
K. Sakoda, Optical Properties of Photonic Crystals, New York: Springer, 2001
S. John and J. Wang, Phys. Rev. Lett., 1990, 64: 2418

doi: 10.1103/PhysRevLett.64.2418
E. P. Petrov, V. N. Bogomolov, I. I. Kalosha, and S. V. Gaponenko, Phys. Rev. Lett., 1998, 81: 77

doi: 10.1103/PhysRevLett.81.77
M. Megens, H. Schriemer, A. Lagendijk, and W. Vos, Phys.Rev. Lett., 1999, 83: 5401

doi: 10.1103/PhysRevLett.83.5401
J. D. Joannopoulos, P. R. Villeneuve, and S. Fan, Nature, 1997, 386: 143

doi: 10.1038/386143a0
H. Kosaka, T. Kawashima, A. Tomita, M. Notomi, T. Tamamura, T. Sato, and S. Kawakami, Appl. Phys. Lett., 1999, 74: 1212

doi: 10.1063/1.123502
H. Kosaka, T. Kawashima, A. Tomita, M. Notomi, T. Tamamura, T. Sato, and S. Kawakami, Phys. Rev. B, 1998, 58: 10096

doi: 10.1103/PhysRevB.58.R10096
M. Notomi, Phys. Rev. B, 2000, 62: 10696

doi: 10.1103/PhysRevB.62.10696
C. Luo, S. G. Johnson, J. D. Joannopoulos, and J. B. Pendry, Phys. Rev. B, 2002, 65: 201104

doi: 10.1103/PhysRevB.65.201104
P. V. Parimi, W. T. Lu, P. Vodo, J. Sokoloff, J. S. Derov, and S. Sridhar, Phys. Rev. Lett., 2004, 92: 127401

doi: 10.1103/PhysRevLett.92.127401
X. Zhang, Front. Phys. China, 2006, 1: 396

doi: 10.1007/s11467-006-0040-x
E. Yablonovitch, T. J. Gmitter, and K. M. Leung, Phys. Rev. Lett., 1991, 67: 2295

doi: 10.1103/PhysRevLett.67.2295
E. Yablonovitch, T. J. Gmitter, R. D. Meade, A. M. Rappe, K. D. Brommer, and J. D. Joannopoulos, Phys. Rev. Lett., 1991, 67: 3380

doi: 10.1103/PhysRevLett.67.3380
H. S?züer and J. Dowling, J. Mod. Opt., 1994, 41: 231

doi: 10.1080/09500349414550291
K. Ho, C. Chan, C. Soukoulis, R. Biswas, and M. Sigalas, Solid State Commun., 1994, 89: 413

doi: 10.1016/0038-1098(94)90202-X
J. Wijnhoven and W. L. Vos, Science, 1998, 281: 802

doi: 10.1126/science.281.5378.802
A. Blanco, E. Chomski, S. Grabtchak, S. John, S. W. Leonard, J. P. Mondia, M. Ibisate, C. Lopez, F. Meseguer, and H. Miguez, Nature, 2000, 405: 437

doi: 10.1038/35013024
V. Berger, O. Gauthier-Lafaye, and E. Costard, J. Appl. Phys., 1997, 82: 60

doi: 10.1063/1.365849
M. Campbell, D. N. Sharp, M. T. Harrison, R. G. Denning, and A. J. Turberfield, Nature, 2000, 404: 53

doi: 10.1038/35003523
K. M. Leung and Y. F. Liu, Phys. Rev. Lett., 1990, 65: 2646

doi: 10.1103/PhysRevLett.65.2646
Z. Zhang and S. Satpathy, Phys. Rev. Lett., 1990, 65: 2650

doi: 10.1103/PhysRevLett.65.2650
K. M. Ho, C. T. Chan, and C. M. Soukoulis, Phys. Rev. Lett., 1990, 65: 3152

doi: 10.1103/PhysRevLett.65.3152
J. B. Pendry and A. MacKinnon, Phys. Rev. Lett., 1992, 69: 2772

doi: 10.1103/PhysRevLett.69.2772
J. Pendry, J. Mod. Opt., 1994, 41: 209

doi: 10.1080/09500349414550281
C. T. Chan, S. Datta, Q. L. Yu, M. Sigalas, K. M. Ho, and C. M. Soukoulis, Physica A, 1994, 211: 411

doi: 10.1016/0378-4371(94)00133-2
P. Tran, Phys. Rev. B, 1995, 52: 10673

doi: 10.1103/PhysRevB.52.10673
N. Stefanou, V. Karathanos, and A. Modinos, J. Phys.: Condens. Matter, 1992, 4: 7389

doi: 10.1088/0953-8984/4/36/013
X. Wang, X. Zhang, Q. Yu, and B. Harmon, Phys. Rev. B, 1993, 47: 4161

doi: 10.1103/PhysRevB.47.4161
L. Wu, Y. Zhong, C. T. Chan, K. S. Wong, and G. P. Wang, Appl. Phys. Lett., 2005, 86: 241102

doi: 10.1063/1.1947369
S. Y. Lin, J. G. Fleming, D. L. Hetherington, B. K. Smith, W. Zubrzycki, S. R. Kurtz, J. Bur, R. Biswas, K. M. Ho, and M. M. Sigalas, Nature, 1998, 394: 251

doi: 10.1038/28343
S. Noda, K. Tomoda, N. Yamamoto, and A. Chutinan, Science, 2000, 289: 604

doi: 10.1126/science.289.5479.604
E. Yablonovitch, Science, 2000, 289: 557

doi: 10.1126/science.289.5479.557
J. Wijnhoven and W. L. Vos, Nature, 1998, 281: 802
T. Y. M. Chan, O. Toader, and S. John, Phys. Rev. E, 2005, 71: 46605

doi: 10.1103/PhysRevE.71.046605
D. N. Sharp, A. J. Turberfield, and R. G. Denning, Phys. Rev. B, 2003, 68: 205102

doi: 10.1103/PhysRevB.68.205102
Y. C. Zhong, S. A. Zhu, H. M. Su, H. Z.Wang, J. M. Chen, Z. H. Zeng, and Y. L. Chen, Appl. Phys. Lett., 2005, 87: 061103

doi: 10.1063/1.2008357
D. Gabor, Nature, 1948, 161: 777

doi: 10.1038/161777a0
A. Ashkin, Phys. Rev. Lett., 1978, 40: 729

doi: 10.1103/PhysRevLett.40.729
M. Burns, J. Fournier, and J. Golovchenko, Phys. Rev. Lett., 1989, 63: 1233

doi: 10.1103/PhysRevLett.63.1233
M. Burns, J. Fournier, and J. Golovchenko, Science, 1990, 249: 749

doi: 10.1126/science.249.4970.749
G. Grynberg, B. Lounis, P. Verkerk, J. Courtois, and C. Salomon, Phys. Rev. Lett., 1993, 70: 2249

doi: 10.1103/PhysRevLett.70.2249
B. Cheng, W. Hu, J. Yang, Z. Li, D. Zhang, and G. Yang, Acta Phys. Sin., 1994, 3: 861
K. Petsas, A. Coates, and G. Grynberg, Phys. Rev. A, 1994, 50: 5173

doi: 10.1103/PhysRevA.50.5173
D. Mei, B. Cheng,W. Hu, Z. Li, and D. Zhang, Opt. Lett., 1995, 20: 429

doi: 10.1364/OL.20.000429
W. Hu, H. Li, B. Cheng, J. Yang, Z. Li, J. Xu, and D. Zhang, Opt. Lett., 1995, 20: 964

doi: 10.1364/OL.20.000964
S. Kirkpatrick, J. Baur, C. Clark, L. Denny, D. Tomlin, B. Reinhardt, R. Kannan, and M. Stone, Appl. Phys. A, 1999, 69: 461

doi: 10.1007/s003390051033
S. Shoji and S. Kawata, Appl. Phys. Lett., 2000, 76: 2668

doi: 10.1063/1.126438
X. Wang, H. Su, L. Zhang, Y. He, X. Zheng, and H. Wang, Appl. Opt., 2001, 40: 5588

doi: 10.1364/AO.40.005588
I. Divliansky, T. Mayer, K. Holliday, and V. Crespi, Appl. Phys. Lett., 2003, 82: 1667

doi: 10.1063/1.1560860
T. Kondo, S. Matsuo, S. Juodkazis, and H. Misawa, Appl. Phys. Lett., 2001, 79: 725

doi: 10.1063/1.1391232
T. Kondo, S. Matsuo, S. Juodkazis, V. Mizeikis, and H. Misawa, Appl. Phys. Lett., 2003, 82: 2758

doi: 10.1063/1.1569987
S. Liu, X. Zhang, and Y. Liu, Proc. SPIE, 2004, 5636: 128

doi: 10.1117/12.574254
Y. Liu, S. Liu, and X. Zhang, Proc. SPIE, 2004, 5636: 677

doi: 10.1117/12.575450
G. Schneider, E. Wetzel, J. Murakowski, and D. Prather, Proc. SPIE, 2005, 5720: 9

doi: 10.1117/12.591090
J. Klein-Wiele and P. Simon, Appl. Phys. Lett., 2003, 83: 4707

doi: 10.1063/1.1631746
Y. V. Miklyaev, Appl. Phys. Lett., 2003, 82: 1284

doi: 10.1063/1.1557328
G. P. Wang, C. Tan, Y. Yi, and H. Shan, J.Mod. Opt., 2003, 50: 2155
D. Prather, Y. Peng, G. Schneider, and J. Murakowski, Proc. SPIE, 2004, 5347: 224

doi: 10.1117/12.538388
L. Z. Cai, X. L. Yang, and Y. R. Wang, J. Opt. Soc. Am. A, 2002, 19: 2238

doi: 10.1364/JOSAA.19.002238
X. Yang, L. Cai, Y. Wang, and Q. Liu, Opt.Commun., 2003, 218: 325

doi: 10.1016/S0030-4018(03)01231-8
H. M. Su, Y. C. Zhong, X. Wang, X. G. Zheng, J. F. Xu, and H. Z. Wang, Phys. Rev. E, 2003, 67: 56619

doi: 10.1103/PhysRevE.67.056619
C. Ullal, M. Maldovan, M. Wohlgemuth, E. Thomas, C. White, and S. Yang, J. Opt. Soc. Am. A, 2003, 20: 948

doi: 10.1364/JOSAA.20.000948
C. K. Ullal, M. Maldovan, E. L. Thomas, G. Chen, Y. J. Han, and S. Yang, Appl. Phys. Lett., 2004, 84: 5434

doi: 10.1063/1.1765734
R. C. Rumpf and E. G. Johnson, J. Opt. Soc. Am. A, 2004, 21: 1703

doi: 10.1364/JOSAA.21.001703
D. C. Meisel, M. Wegener, and K. Busch, Phys. Rev. B, 2004, 70: 165104

doi: 10.1103/PhysRevB.70.165104
J. Moon, S. Yang, D. Pine, and W. Chang, Appl. Phys. Lett., 2004, 85: 4184

doi: 10.1063/1.1813644
O. Toader, T. Y. M. Chan, and S. John, Appl. Phys. Lett., 2006, 89: 101117

doi: 10.1063/1.2347112
D. Chanda and P. Herman, Appl. Phys. Lett., 2007, 91: 061122

doi: 10.1063/1.2768867
E. Ozbay, A. Abeyta, G. Tuttle, M. Tringides, R. Biswas, C. T. Chan, C. M. Soukoulis, and K. M. Ho, Phys. Rev. B, 1994, 50: 1945

doi: 10.1103/PhysRevB.50.1945
S. Shoji, H. B. Sun, and S. Kawata, Appl. Phys. Lett., 2003, 83: 608

doi: 10.1063/1.1595720
Y. Lin, P. R. Herman, and K. Darmawikarta, Appl. Phys. Lett., 2005, 86: 071117

doi: 10.1063/1.1865329
Y. Lin, D. Rivera, and K. P. Chen, Opt. Express, 2006, 14: 887

doi: 10.1364/OPEX.14.000887
Y. K. Pang, J. C. Lee, C. T. Ho, and W. Y. Tam, Opt. Express, 2006, 14: 9013

doi: 10.1364/OE.14.009013
S. Lin, J. Fleming, R. Lin, M. Sigalas, R. Biswas, K. Ho, J. Opt. Soc. Am. B, 2001, 18: 32

doi: 10.1364/JOSAB.18.000032
O. Toader, T. Y. M. Chan, and S. John, Phys. Rev. Lett., 2004, 92: 43905

doi: 10.1103/PhysRevLett.92.043905
L. Yuan, G. P. Wang, and X. Huang, Opt. Lett., 2003, 28: 1769

doi: 10.1364/OL.28.001769
L. Z. Cai, X. L. Yang, and Y. R. Wang, Opt. Lett., 2002, 27: 900

doi: 10.1364/OL.27.000900
X. Wang, J. Xu, H. Su, Y. He, S. Jiang, H. Wang, Z. Zeng, and Y. Chen, Acta Phys. Sin., 2002, 51: 527
Y. Zhong, L. Wu, H. Su, K. S. Wong, and H. Wang, Opt. Express, 2006, 14: 6837

doi: 10.1364/OE.14.006837
H. Misawa, T. Kondo, S. Juodkazis, V. Mizeikis, and S. Matsuo, Opt. Express, 2006, 14: 7943

doi: 10.1364/OE.14.007943
Y. Liu, S. Liu, and X. Zhang, Appl. Opt., 2006, 45: 480

doi: 10.1364/AO.45.000480
N. D. Lai,W. P. Liang, J. H. Lin, C. C. Hsu, and C. H. Lin, Opt. Express, 2005, 13: 9605

doi: 10.1364/OPEX.13.009605
Y. Zhong, S. Zhu, and H. Wang, Chin. Phys. Lett., 2005, 22: 369

doi: 10.1088/0256-307X/22/2/028
W. Mao, G. Liang, H. Zou, and H. Wang, Opt.Lett., 2006, 31: 1708

doi: 10.1364/OL.31.001708
W. D. Mao, G. Q. Liang, Y. Y. Pu, H. Z. Wang, and Z. Zeng, Appl. Phys. Lett., 2007, 91: 261911

doi: 10.1063/1.2827565
W. D. Mao, J. W. Dong, Y. C. Zhong, G. Q. Liang, and H. Z. Wang, Opt. Express, 2005, 13: 2994

doi: 10.1364/OPEX.13.002994
W. Y. Tam, Appl. Phys. Lett., 2006, 89: 251111

doi: 10.1063/1.2408651
X. Wang, C. Y. Ng, W. Y. Tam, C. T. Chan, and P. Sheng, Adv. Mater., 2003, 15: 1526

doi: 10.1002/adma.200305263
W. Mao, G. Liang, H. Zou, R. Zhang, H. Wang, and Z. Zeng, J. Opt. Soc. Am. B, 2006, 23: 2046

doi: 10.1364/JOSAB.23.002046
Y. Yang, S. Zhang, and G. P. Wang, Appl. Phys. Lett., 2006, 88: 251104

doi: 10.1063/1.2216871
J. Xu, R. Ma, X. Wang, and W. Y. Tam, Opt. Express, 2007, 15: 4287

doi: 10.1364/OE.15.004287
X. Wang, J. Xu, J. C. W. Lee, Y. K. Pang, W. Y. Tam, C. T. Chan, and P. Sheng, Appl. Phys. Lett., 2006, 88: 051901

doi: 10.1063/1.2168487
Y. Yang, Q. Li, and G. P. Wang, Appl. Phys. Lett., 2008, 93: 061112

doi: 10.1063/1.2969071
Y. Yang and G. P. Wang, Appl. Phys. Lett., 2006, 89: 111104

doi: 10.1063/1.2353804
L. Wu, Y. Zhong, K. S. Wong, G. P. Wang, and L. Yuan, Appl. Phys. Lett., 2006, 88: 091115

doi: 10.1063/1.2181270
G. Liang, W. Mao, Y. Pu, H. Zou, H. Wang, and Z. Zeng, Appl. Phys. Lett., 2006, 89: 041902

doi: 10.1063/1.2234743
Y. Yang, Q. Li, and G. Wang, Opt. Express, 2008, 16: 11275

doi: 10.1364/OE.16.011275
D. Xia, J. Zhang, X. He, and S. Brueck, Appl. Phys. Lett., 2008, 93: 071105

doi: 10.1063/1.2971202
N. Tétreault, G. von Freymann, M. Deubel, M. Hermatschweiler, F. Pérez-Willard, S. John, M. Wegener, and G. Ozin, Adv. Mater., 2006, 18: 457
J. King, E. Graugnard, O. Roche, D. Sharp, J. Scringeout, R. Denning, A. Turberfield, and C. Summers, Adv. Mater., 2006, 18: 1561

doi: 10.1002/adma.200502287
J. H. Moon, S. Yang,W. Dong, J. W. Perry, A. Adibi, and S. M. Yang, Opt. Express, 2006, 14: 6297

doi: 10.1364/OE.14.006297
K. Kaneko, H. Sun, X. Duan, and S. Kawata, Appl. Phys. Lett., 2003, 83: 1426

doi: 10.1063/1.1601302
Y. Yang, G. Wang, J. Xie, and S. Zhang, Appl. Phys. Lett., 2005, 86: 173108

doi: 10.1063/1.1920423
J. G. Fleming, S. Y. Lin, I. El-Kady, R. Biswas, and K. M. Ho, Nature, 2002, 417: 52

doi: 10.1038/417052a
J. Zhou, Y. Zhou, S. Ng, H. Zhang, W. Que, Y. Lam, Y. Chan, and C. Kam, Appl. Phys. Lett., 2000, 76: 3337

doi: 10.1063/1.126641
R. Ma, J. Xu, and W. Y. Tam, Appl. Phys. Lett., 2006, 89: 081116

doi: 10.1063/1.2240646
Z. Ren, T. Zhai, Z.Wang, J. Zhou, and D. Liu, Adv. Mater., 2008, 20: 2337

doi: 10.1002/adma.200702698
X. Wang, J. F. Xu, H. M. Su, Z. H. Zeng, Y. L. Chen, H. Z. Wang, Y. K. Pang, and W. Y. Tam, Appl. Phys. Lett., 2003, 82: 2212

doi: 10.1063/1.1565682
Y. C. Chen, J. B. Geddes Iii, J. T. Lee, P. V. Braun, and P. Wiltzius, Appl. Phys. Lett., 2007, 91: 241103

doi: 10.1063/1.2820449
J. Chen, W. Jiang, X. Chen, L. Wang, S. Zhang, and R. Chen, Appl. Phys. Lett., 2007, 90: 093102

doi: 10.1063/1.2709641
J. Zheng, Z. Ye, X. Wang, and D. Liu, Phys.Lett. A, 2004, 321: 120

doi: 10.1016/j.physleta.2003.11.041
T. Zhai, Z. Wang, R. Zhao, X. Ren, and D. Liu, IEEE J. Quantum Electron., 2009, 45: 1297

doi: 10.1109/JQE.2009.2023806
R. Jakubiak, T. Bunning, R. Vaia, L. Natarajan, and V. Tondiglia, Adv. Mater., 2003, 15: 241

doi: 10.1002/adma.200390056
P. Mach, P. Wiltzius, M. Megens, D. Weitz, K. Lin, T. Lubensky, and A. Yodh, Phys. Rev. E, 2002, 65: 31720

doi: 10.1103/PhysRevE.65.031720
R. Jakubiak, V. P. Tondiglia, L. V. Natarajan, R. L. Sutherland, P. Lloyd, T. J. Bunning, and R. A. Vaia, Adv. Mater., 2005, 17: 2807

doi: 10.1002/adma.200501291
Z. Ren, Z. Wang, T. Zhai, H. Gao, D. Liu, and X. Zhang, Phys. Rev. B, 2007, 76: 035120

doi: 10.1103/PhysRevB.76.035120
T. Zhai, Z. Wang, R. Zhao, J. Zhou, D. Liu, and X. Zhang, Appl. Phys. Lett., 2008, 93: 201902

doi: 10.1063/1.3031671
T. Zhai, X. Ren, Z.Wang, J. Zhou, and D. Liu, IEEE Photo. Tech. Lett., 2009, 21: 1849

doi: 10.1109/LPT.2009.2033127
J. Hung, M. Kok, and W. Tam, Appl. Phys. Lett., 2009, 94: 014102

doi: 10.1063/1.3064165
Y. Chassagneux, R. Colombelli, W. Maineult, S. Barbieri, H. Beere, D. Ritchie, S. Khanna, E. Linfield, and A. Davies, Nature, 2009, 457: 174

doi: 10.1038/nature07636
H. Matsubara, S. Yoshimoto, H. Saito, Y. Jianglin, Y. Tanaka, and S. Noda, Science, 2008, 319: 445

doi: 10.1126/science.1150413
O. Painter, R. K. Lee, A. Scherer, A. Yariv, J. D. O'Brien, P. D. Dapkus, and I. Kim, Science, 1999, 284: 1819

doi: 10.1126/science.284.5421.1819
M. Meier, A. Mekis, A. Dodabalapur, A. Timko, R. Slusher, J. Joannopoulos, and O. Nalamasu, Appl. Phys. Lett., 1999, 74: 7

doi: 10.1063/1.123116
M. Imada, S. Noda, A. Chutinan, T. Tokuda, M. Murata, and G. Sasaki, Appl. Phys. Lett., 1999, 75: 316

doi: 10.1063/1.124361
S. Noda, M. Yokoyama, M. Imada, A. Chutinan, and M. Mochizuki, Science, 2001, 293: 1123

doi: 10.1126/science.1061738
M. Notomi, H. Suzuki, and T. Tamamura, Appl. Phys. Lett., 2001, 78: 1325

doi: 10.1063/1.1352671
M. Notomi, H. Suzuki, T. Tamamura, and K. Edagawa, Phys. Rev. Lett., 2004, 92: 123906

doi: 10.1103/PhysRevLett.92.123906
T. Komikado, S. Yoshida, and S. Umegaki, Appl. Phys. Lett., 2006, 89: 61123

doi: 10.1063/1.2336740
M. Kok, W. Lu, J. Lee, W. Tam, G. Wong, and C. Chan, Appl. Phys. Lett., 2008, 92: 151108

doi: 10.1063/1.2907488
M. Kok, W. Lu, W. Tam, and G. Wong, Opt.Express, 2009, 17: 7275

doi: 10.1364/OE.17.007275
T. Zhai, Y. Zhou, S. Chen, D. Liu, and X. Zhang, to be published
T. Zhai, Y. Zhou, S. Chen, Z. Wang, J. Shi, D. Liu, and X. Zhang, to be published
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed