Fibre-optic nonlinear optical microscopy and endoscopy

Journal of Microscopy

Volumn 226, Issue 3, 2007, Pages 195-206

  Fu, L ^a   Gu, M ^a  

^a SWINBURNE UNIVERSITY OF TECHNOLOGY   (Australia)

Author keywords

Endoscopy; Fibre optic imaging; Nonlinear optical microscopy; Optical fibres

Indexed keywords

ANIMALS; ENDOSCOPY; FIBER OPTICS; MICROSCOPES; OPTICAL DATA STORAGE; OPTICAL MICROSCOPY; PHOTONIC CRYSTAL FIBERS; TISSUE;

CELLULAR IMAGING; CONVENTIONAL OPTICAL MICROSCOPES; FIBER OPTICS COMPONENTS; FIBER OPTICS IMAGING; FIBER-OPTICS; HIGH-RESOLUTION IMAGING; LABORATORY TOOLS; NON-LINEAR OPTICAL; NONLINEAR OPTICAL MICROSCOPY; THICK-TISSUE;

NONLINEAR OPTICS;

ENDOSCOPY; FIBER OPTICS; IMAGING SYSTEM; MICROELECTROMECHANICAL SYSTEM; MICROSCOPY; PRIORITY JOURNAL; REVIEW; THREE DIMENSIONAL IMAGING;

ANIMALIA;

EID: 34347380930     PISSN: 00222720     EISSN: 13652818     Source Type: Journal    
DOI: 10.1111/j.1365-2818.2007.01777.x     Document Type: Review

References (111)

1. Agrawal, G.P. (1989) Nonlinear Fiber Optics. Academic, San Diego, CA.
2. Aguirre, D., Herz, P.R., Chen, Y., Fujimoto, J.G., Piyawattanametha, W., Fan, L., Hsu, S., Fujino, M., Wu, M.C. & Kopf, D. (2005) Ultrahigh resolution OCT imaging with a two-dimensional MEMS scanning endoscope. Advanced Biomedical and Clinical Diagnostic Systems III (ed. by T. Vo-Dinh, W.S. Grundfest, D.A. Benaron & G.E. Cohn Proc. SPIE. 5692, 277 282.
3. Barad, Y., Eizenberg, H., Horowitz, M. & Silberberg, Y. (1997) Nonlinear scanning laser microscopy by third-harmonic generation. Appl. Phys. Lett., 70, 922 924.
4. Bird, D. & Gu, M. (2002a) Fibre-optic two-photon scanning fluorescence microscopy. J. Microsc. 208, 35 48.
5. Bird, D. & Gu, M. (2002b) Compact two-photon fluorescence microscope based on a single-mode fiber coupler. Opt. Lett. 27, 1031 1033
6. Bird, D. & Gu, M. (2002c) Resolution improvement in two-photon fluorescence microscopy with a single-mode fiber. Appl. Opt. 41, 1852 1857.
7. Bird, D. & Gu, M. (2003) Two-photon fluorescence endoscopy with a micro-optic scanning head. Opt. Lett. 28, 1552 1554.
8. Bjarklev, A., Broeng, J. & Bjarklev, A.S. (2003) Photonic Crystal Fibers. Kluwer Academic Publishers, Norwell, MA.
9. Boppart, S.A., Deutsch, T.F. & Rattner, D.W. (1999) Optical imaging technology in minimally invasive surgery. Surg. Endosc. 13, 718 722.
10. Brown, E.B., Campbell, R.B., Tsuzuki, Y., Xu, L., Carmeliet, P., Fukumura, D. & Jain, R.K. (2001) In vivo measurement of gene expression, angiogenesis and physiological function in tumors using multiphoton laser scanning microscopy. Nat. Medicine 7, 864 868.
11. Campagnola, P.J., Wei, M., Lewis, A. & Loew, L.M. (1999) High-resolution nonlinear optical imaging of live cells by second harmonic generation. Biophys. J. 77, 3341 3349.
12. Campagnola, P.J., Millard, A.C., Terasaki, M., Hoppe, P.E., Malone, C.J. & Mohler, W.A. (2002) Three-dimensional high-resolution second-harmonic generation imaging of endogenous structural proteins in biological tissues. Biophys. J. 81, 493 508.
13. Campagnola, P.J. & Loew, L.M. (2003) Second harmonic imaging microscopy for visualizing biomolecular arrays in cells, tissues and organisms. Nat. Biotech. 21, 1356 1360.
14. Cheng, J.X. & Xie, X.S. (2004) Coherent anti-Stokes Raman scattering microscopy: Instrumentation, Theory, and Applications. J. Phys. Chem. B 108, 827 840.
15. Choi, H., Chen, S., Kim, D., So, P.T.C. & Culpepper M.L. (2006) Design of nonlinear endomicroscope biopsy probe. Biomedical Optics Topical Meeting. Fort Lauderdale, FL.
16. Chu, S.W., Chen, S.Y., Chern, G.W., Tsai, T.H., Chen, Y.C., Lin, B.L. & Sun, C.K. (2004) Studies of x(2)/x(3) tensors in submicron-scaled bio-tissues by polarization harmonics optical microscopy. Biophys. J. 86, 3914 3922.
17. Condeelis, J. & Segall, J.E. (2003) Intravital imaging of cell movement in tumors. Nat. Rev. Cancer 3, 921 930.
18. Dabbs, T. & Glass, M. (1992) Fibre-optic confocal microscope: FOCON. Appl. Opt. 31, 3030 3035.
19. Deng, X., Williams, E.D., Thompson, E.W., Gan, X. & Gu, M. (2002a) Second-harmonic generation from biological tissues: Effect of excitation wavelength. Scanning 24, 175 178.
20. Deng, X., Gan, X. & Gu, M. (2002b) Multi-photon fluorescence microscopic imaging through double-layered turbid tissue media. J. Appl. Phys. 91, 4659 4665.
21. Denk, W., Strickler, J.H. & Webb, W.W. (1990) Two-photon laser scanning fluorescence microscopy. Science 248, 73 75.
22. Dudley, J. M., Provino, L., Grossard, N., Maillotte, J., Windeler, R.S., Eggleton, B.J. & Coen, S. (2002) Supercontinuum generation in air-silica microstuctured fibers with nanosecond and femtosecond pulse pumping. J. Opt. Soc. Am. B 19, 765 771.
23. Dudley, J. M., Genty, G. & Coen, S. (2006) Supercontinuum generation in photonic crystal fiber. Rev. Modern Phys. 78, 1135 1184.
24. Duncan, M., Reintjes, J., Manuccia, T.J. (1982) Scanning coherent anti-Stokes Raman microscope. Opt. Lett. 7, 350 352.
25. Evans, C.L., Potma, E.O., Puoris'haag, M., Cote, D., Lin, C.P. & Xie, X.S. (2005) Chemical imaging of tissue in vivo with video-rate coherent anti-Stokes Raman scattering microscopy. Proc. Natl. Acad. Sci. USA. 102, 16807 16812.
26. Flusberg, B.A., Cocker, E.D., Piyawattanametha, W., Jung, J.C., Cheung, E.L.M. & Schnitzer, M.J. (2005a) Fiber-optic fluorescence imaging. Nat. Methods. 2, 941 950.
27. Flusberg, B.A., Jung, J.C., Cocker, E.D., Anderson, E.P. & Schnitzer, M.J. (2005b) In vivo brain imaging using a portable 3.9 gram two-photon fluorescence microendoscope. Opt. Lett. 30, 2272 2274.
28. Franken, P.A., Hill, A.E., Peters, C.W. & Weinreich, G. (1961) Generation of optical harmonics. Phys. Rev. Lett. 7, 118 120.
29. Fu, L., Gan, X. & Gu, M. (2005a) Nonlinear optical microscopy based on double-clad photonic crystal fibers. Opt. Express. 13, 5528 5534.
30. Fu, L., Gan, X. & Gu, M. (2005b) Characterization of the GRIN lens-fiber spacing toward applications in two-photon fluorescence endoscopy. Appl. Opt. 44, 7270 7274.
31. Fu, L., Gan, X. & Gu, M. (2005c) Use of a single-mode fiber coupler for second harmonic generation microscopy. Opt. Lett. 30, 385 387.
32. Fu, L.Z, Gan, X., Bird, D. & Gu, M. (2005d) Polarisation characteristics of a 1×2 fiber coupler under femtosecond pulsed and continuous wave illumination. Optics Laser Technol. 37, 494 497.
33. Fu, L., Jain, A., Xie, H., Cranfield, C. & Gu, M. (2006) Nonlinear optical endoscopy based on a double-clad photonic crystal fiber and a MEMS mirror. Opt. Express. 14, 1027 1032.
34. Fu, L. & Gu, M. (2006) A double-clad photonic crystal fiber coupler for compact nonlinear optical microscopy imaging. Opt. Lett. 31, 1471 1473.
35. Furihata, H. (2001) New technologies in endoscopic surgery. Min. Invas. Ther. & Allied. Technol. 10, 199 203.
36. Gan, X. & Gu, M. (2000) Fluorescence microscopic imaging through tissue-like turbid media. J. Appl. Phys. 87, 3214 3221.
37. George, M. (2004) Optical methods and sensors for in situ histology in surgery and endoscopy. Min. Invas. Ther. & Allied. Technol. 13, 95 104.
38. Göbel, W., Nimmerjahn, A. & Helmchen, F. (2004a) Distortion-free delivery of nanojoule femtosecond pulses from a Ti:sapphire laser through a hollow-core photonic crystal fiber. Opt. Lett. 29, 1285 1287.
39. Göbel, W., Kerr, J.N.D., Nimmerjahn, A. & Helmchen, F. (2004b) Miniaturized two-photon microscope based on a flexible coherent fiber bundle and a gradient-index lens objective. Opt. Lett. 29, 2521 2523.
40. Gu, M. 1996) Principles of three-dimensional imaging in confocal microscopes, World Scientific Publishing, Singapore.
41. Gu, M. & Bird, D. (2003) Three-dimensional optical-transfer-function analysis of fiber-optical two-photon fluorescence microscopy. J. Opt. Soc. Am. A. 20, 941 947.
42. Gu, M. & Fu, L. (2006) Three-dimensional image formation in fiber-optical second-harmonic-generation microscopy. Opt. Express. 14, 1175 1181.
43. Gu, M. & Sheppard, C. J. R. (1993) Experimental investigation of fibre-optical confocal scanning microscopy: Including a comparison with pinhole detection, Micron. 24, 557 565.
44. Gu, M., Sheppard, C. J. R., & Gan, X. (1991a) Image formation in a fiber-optical confocal scanning microscope. J. Opt. Soc. Am. A. 8, 1755 1761.
45. Gu, M., Gan, X. & Sheppard, C. J. R. (1991b) Three-dimensional coherent transfer functions in fiber-optical confocal scanning microscopes. J. Opt. Soc. Am. A. 8, 1019 1025.
46. Gu, M., Gan, X., Kisteman, A. & Xu, M. (2000) Comparison of penetration depth between two-photon excitation in imaging through turbid tissue media. Appl. Phys. Letts. 77, 1551 1553.
47. Hell, S.W., Bahlmann, K., Schrader, M., Soini, A., Malak, H., Gryczynski, I. & Lakowicz, J.R. (1996) Three-photon excitation in fluorescence microscopy. J. Biomed. Opt. 1, 71 74.
48. Hellwarth, R. & Christensen, P. (1974) Nonlinear optical microscopic examination of structure in polycrystalline ZnSe. Opt. Commun. 12, 318 322.
49. Helmchen, F., Fee, M.S., Tank, D.W. & Denk, W. (2001) A miniature head-mounted two-photon microscope: High-resolution brain imaging in freely moving animals. Neuron. 31, 903 912.
50. Helmchen, F., Tank, D.W., Denk, W. (2002) Enhanced two-photon excitation through optical fiber by single-mode propagation in a large core. Appl. Opt. 41, 2930 2934.
51. Helmchen, F. & Denk, W. (2005) Deep tissue two-photon microscopy. Nat. Methods 2, 932 940.
52. Herz, P., Chen, Y., Aguirre, A., Schneider, K., Hsiung, P., Fujimoto, J., Madden, K., Schmitt, J., Goodnow, J. & Petersen, C. (2004) Micromotor endoscope catheter for in vivo, ultrahigh-resolution optical coherence tomography. Opt. Lett. 29, 2261 2263.
53. Hori, T., Nishizawa, N. & Goto, T. (2004) Experimental and numerical analysis of widely broadened supercontinuum generation in highly nonlinear dispersion-shifted fiber with a femtosecond pulse. J. Opt. Soc. Am. B 21, 1969 1980.
54. Hoy, C.L., Durr, N.J., Douglass, S., Mallick, S., Solgaard, O.D. & Ben-Yakar, A. (2007) A compact 15-mm wide two-photon Microscope for imaging and femtosecond laser microsurgery. Multiphoton Microscopy in the Biomedical Sciences VII (ed. by A. Periasamy & P.T.C. So Proc. SPIE.
55. Isobe, K., Watanabe, W., Matsunaga, S., Higashi, T., Fukui, K. & Itoh, K. (2005) Multi-spectral two-photon excited fluorescence microscopy using supercontinuum light source. J. J. Appl. Phys. 44, L167 L169.
56. Jain, A., Kopa, A., Pan, Y., Fedder, G.K. & Xie, H. (2004) A two-axis electrothermal micromirror for endoscopic optical coherence tomography. IEEE J. Sel. Top. Quantum Electron. 10, 636 642.
57. Jain, R.K., Munn, L.L. & Fukumura, D. (2002) Dissecting tumor pathophysiology using intravital microscopy. Nat. Rev. Cancer 2, 266 275.
58. Jung, J.C. & Schnitzer, M.J. (2003) Multiphoton endoscopy. Opt. Lett. 28, 902 904.
59. Jung, J.C., Mehta, A.D., Aksay, E., Stepnoski, R. & Schinitzer, M.J. (2004) In vivo mammalian brain imaging using one- and two-photon fluorescence microendoscopy. J. Neurophysiol. 92, 3121 3133.
60. Kaiser, W. & Garrett, C.G.B. (1961) Two-photon excitation in CaF2: Eu2+. Phys. Rev. Lett. 7, 229 231.
61. Kano, H. & Hamaguchi, H. (2006) In vivo multi-nonlinear optical imaging of a living cell using a supercontinuum light source generated from a photonic crystal fibre. Opt. Express 14, 2798 2804.
62. Kim, D., Kim, K.H., Yazdanfar, S. & So, P.T.C. (2005) Optical biopsy in high-speed handheld miniaturized multifocal multiphoton microscopy. Multiphoton Microscopy in the Biomedical Sciences V (ed. by A. Periasamy & P.T.C. So Proc. SPIE. 5700, 14 22.
63. Kimura, S. & Wilson, T. (1991) Confocal scanning optical microscope using single-mode fiber for signal detection. Appl. Opt. 30, 2143 2150.
64. Knight, J.C. & Russell, P. (2002) New ways to guide light. Science 296, 276 277.
65. Knight, J. C. (2003) Photonic crystal fibers. Nature 424, 847 851.
66. Knittel, J., Schnieder, L., Buess, G., Messerschmidt, B. & Possner, T. (2001) Endoscope-compatible confocal microscope using a gradient index-lens system. Opt. Commun. 188, 267 273.
67. Kong, G., Kim, J., Choi, H., Im, J.E., Park, B., Paek, U. & Lee, B.H. (2006) Lensed photonic crystal fiber obtained by use of an arc discharge. Opt. Lett. 31, 894 896.
68. König, K., Ehlers, A., Riemann, I., Schenkl, S., Bückle, R. & Kaatz, M. (2007) Clinical two-photon microendoscopy. Microsco. Res. and Tech. 70, 398 402.
69. Lane, P.M., Dlugan, A.L.P., Richards-Kortum, R. & MacAulay, C.E. (2000) Fibre-optic confocal microscopy using a spatial light modulator. Opt. Lett. 25, 1780 1782.
70. Legare, F., Evans, C.L., Ganikhanov, F. & Xie, X.S. (2006) Towards CARS endoscopy. Opt. Express 14, 4427 4432.
71. Levene, M.J., Dombeck, D.A., Kasischke, K.A., Molloy, R.P. & Webb, W.W. (2004) In vivo multiphoton microscopy of deep brain tissue. J. Neurophysiol. 91, 1908 1912.
72. Maker, P.D. & Terhune, R.W. (1965) Study of optical effects due to an induced polarization third order in the electric field strength. Phys. Rev. 137, A801 818.
73. McConnell, G. & Riis, E. (2004a) Two-photon laser scanning fluorescence microscopy using photonic crystal fibre. J. Biomed. Opt. 9, 922 927.
74. McConnell, G. & Riis, E. (2004b) Photonic crystal fibre enables short-wavelength two-photon laser scanning fluorescence microscopy with fura-2. Phys. Med. Biol. 49, 4757 4763.
75. Mehta, A.D., Jung, J.C., Flusberg, B.A. & Schnitzer, M.J. (2004) Fiber optic in vivo imaging in the mammalian nervous system. Curr. Opin. Neurobiol. 14, 1 12.
76. Myaing, M.T., Ye, J.Y., Norris, T.B., Thomas, T., Baker, J.R., Wadsworth, W.J., Bouwmans, G., Knight, J.C. & Russell, P. (2003) Enhanced two-photon biosensing with double-clad photonic crystal fibers. Opt. Lett. 28, 1224 1226.
77. Myaing, M.T., MacDonald, D.J. & Li, X. (2006) Fiber-optic scanning two-photon fluorescence endoscope. Opt. Lett. 31, 1076 1078.
78. Nishizawa, N., Chen, Y., Hsiung, P., Ippen, E.P. & Fujimoto, J.G. (2004) Real-time, ultrahigh-resolution, optical coherence tomography with an all-fiber, femtosecond fiber laser continuum at 1.5 um. Opt. Lett. 29, 2846 2848.
79. Ouzounov, D.G., Moll, K.D., Foster, M.A., Zipfel, W.R., Webb, W.W. & Gaeta, A.L. (2002) Delivery of nanojoule femtosecond pulses through large-core microstructured fibers. Opt. Lett. 27, 1513 1515.
80. Palero, J.A., Boer, V.O., Vijvergerg, J.C., Gerritsen, H.C. & Sterenborg, H.J.C.M. (2005) Short-wavelength two-photon excitation fluorescence microscopy of tryptophan with a photonic crystal fiber based light source. Opt. Express. 13, 5363 5368.
81. Piyawattanametha, W., Barretto, R.P.J., Ko, T., Flusberg, B.A., Cocker, E.D., Ra, H., Lee, D., Solgaard, O. & Schnitzer, M.J. (2006) Fast-scanning two-photon fluorescence imaging based on a microelectromechanical systems (MEMS) two-dimensional scanning mirror. Opt. Lett. 31, 2018 2020.
82. Reed, W.A., Yan, M.F. & Schnitzer, M.J. (2002) Gradient-index fiber-optic microprobes for minimally invasive in vivo low-coherence interferometry. Opt. Lett. 27, 1794 1796.
83. Reeves, W.H., Skryabin, D.V., Biancalana, F., Knight, J.C., Russell, P., Omenetto, F.G., Efimov, A. & Taylor, A.J. (2003) Transformation and control of ultrashort pulses in dispersion-engineered photonic crystal fibres. Nature 424, 511 515.
84. Rouse, A.R., Kano, A., Udovich, J.A., Kroto, A.M. & Gmitro, A.F. (2004) Design and demonstration of a miniature catheter for a confocal microendoscope. Appl. Opt. 43, 5763 5771.
85. Russell, P. (2003) Photonic crystal fibers. Science 299, 358 362.
86. Saleh, B.E.A. & Teich, M.C. (1991) Fundamentals of Photonics. John Wiley, New York.
87. Schilders, S. & Gu, M. (1999) Three-dimensional autofluorescence spectroscopy of rat skeletal muscle tissue under two-photon excitation. Appl. Opt. 38, 720 723.
88. Shen, Y. R. (1984) The Principles of Nonlinear Optics. J. Wiley, New York.
89. Shi, K., Li, P., Yin, S. & Liu, Z. (2004) Chromatic confocal microscopy using supercontinuum light. Opt. Express. 12, 2096 2101.
90. Singh S. & Brandley, L.T. (1964) Three-photon absorption in Napthalene crystals by laser excitation. Phys. Rev. Lett. 12, 612 614.
91. Stoller, P., Reiser, K.M., Celliers, P.M. & Rubenchik, A.M. (2002a) Polarization-modulated second harmonic generation in collagen. Biophys. J. 82, 3330 3342.
92. Stoller, P., Kim, B.M., Rubenchik, A.M., Reiser, K.M. & Silva, L.B.D. (2002b) Polarization-dependent optical second-harmonic imaging of a rat-tail tendon. J. Biomed. Opt. 7, 205 214.
93. Sung, K.B., Liang, C., Descour, M., Collier, T., Follen, M., Malpica, A. & Richards-Kortum, R. (2002a) Near real time in vivo fibre optic confocal microscopy: Sub-cellular structure resolved. J. Microsc. 207, 137 145.
94. Sung, K., Liang, C., Descour, M., Collier, T., Follen, M. & Richards-Kortum, R. (2002b) Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues. IEEE Trans. Biomed. Eng. 49, 1168 1172.
95. Tai, S.P., Chan, M.C., Tsai, T.H., Guol, S.H., Chen, L.J. & Sun, C.K. (2004) Two-photon fluorescence microscope with a hollow-core photonic crystal fiber. Opt. Express 12, 6122 6128.
96. Terhune, R.W., Maker, P.D. & Savage, C.M. (1962) Optical harmonic generation in Calcite. Phys. Rev. Lett. 8, 404 406.
97. Theer, P., Hasan, M.T. & Denk, W. (2003) Two-photon imaging to a depth of 1000 um in living brains by use of a Ti:Al2O3 regenerative amplifer. Opt. Lett. 28, 1022 1024.
98. Tran, P., Mukai, D., Brenner, M. & Chen, Z. (2004) In vivo endoscopic optical coherence tomography by use of a rotational microelectromechanical system probe. Opt. Lett. 29, 1236 1238.
99. Wadsworth, W.J., Ortigosa-Blanch, A., Knight, J.C., Birks, T.A., Man, T.M. & Russell, P. (2002) Supercontinuum generation in photonic crystal fibers and optical fiber tapers: A novel light source. J. Opt. Soc. Am. B 19, 2148 2155.
100. Williams, R.M., Zipfel, W.R. & Webb, W.W. (2001) Multiphoton microscopy in biological research. Curr. Opin. Chem. Biol. 5, 603 608.
101. Wolleschensky, R., Feurer, T., Sauerbrey, R. & Simon, U. (1998) Characterization and optimization of a laser-scanning microscope in the femtosecond regime. Appl. Phys. B 67, 87 94.
102. Wolleschensky, R., Dickinson, M.E. & Fraser, S.E. (2002) Group-velocity dispersion and fiber delivery in multiphoton laser scanning microscopy. In Confocal and Two-photon Microscopy: Foundations, Applications and Advances, pp. 171 190. Wiley-Liss, New York.
103. Xie, H., Pan, Y. & Fedder, G.K. (2003) Endoscopic optical coherence tomographic imaging with a CMOS-MEMS micromirror. Sensors and Actuators 103, 237 241.
104. Xu M., Williams, E. D., Thompson, R. & Gu, M. (2000) Effect of handling and fixation processes on fluorescence spectroscopy of rat skeletal muscles under two-photon excitation. Appl. Opt. 39, 6312 6317.
105. Yasui, T., Tohno, Y. & Araki, T. (2004) Determination of collagen fiber orientation in human tissue by use of polarization measurement of molecular second-harmonic-generation light. Appl. Opt. 43, 2861 2867.
106. Ye, J.Y., Myaing, M.T., Thomas, T.P., Majoros, I., Koltyar, A., Baker, J.R., Wadsworth, W.J., Bouwmans, G., Knight, J.C., Russell, P. & Norris, T.B. (2005) Development of a double-clad photonic crystal fiber based scanning microscope. Multiphoton Microscopy in the Biomedical Sciences V (ed. by A. Periasamy & P.T.C. So Proc. SPIE. 5700, 23 27.
107. Yeh, A.T., Nassif, N., Zoumi, A. & Tromberg, B.J. (2002) Selective corneal imaging using combined second-harmonic generation and two-photon excited fluorescence. Opt. Lett. 27, 2082 2084.
108. Zipfel, W.R., Williams, R.M. & Webb, W.W. (2003a) Nonlinear magic: Multiphoton microscopy in the biosciences. Nat. Biotech. 21, 1369 1377.
109. Zipfel, W.E., Williams, R.M., Christie, R., Nikitin, A.Y., Hyman, B.T. & Webb, W.W. (2003b) Live tissue intrinsic emission microscopy using multiphoton-excited native fluorescence and second harmonic generation. Proc. Natl. Acad. Sci. USA 100, 7075 7080.
110. Zoumi, A., Yeh, A. & Tromberg, B.J. (2002) Imaging cells and extracellular matrix in vivo by using second-harmonic generation and two-photon excited fluorescence. Proc. Natl. Acad. Sci. USA 99, 11014 11019.
111. Zoumi, A., Lu, X., Kassab, G.S. & Tromberg, B.J. (2004) Imaging coronary artery microstructure using second-harmonic and two-photon fluorescence microscopy. Biophys. J. 87, 2778 2786.