[1] [1] D. O'Malley, "Imaging in depth: Controversies and opportunities," Methods Cell Biol. 89, Ch. 5, 95–128 (2008).

[2] [2] P. Theer, M. T. Hasan, W. Denk, "Two-photon imaging to a depth of 1000 micron in living brains by use of a Ti:Al2O3 regenerative amplifier," Opt. Lett. 28(12), 1022–1024 (2003).

[3] [3] D. Kobat, M. E. Durst, N. Nishimura, A. W. Wong, C. B. Schaffer, C. Xu, "Deep tissue multiphoton microscopy using longer wavelength excitation," Opt. Express 17, 13354–13364 (2009).

[4] [4] R. Cicchi, D. D. Sampson, D. Massi, F. S. Pavone, "Contrast and depth enhancement in two-photon microscopy of human skin ex vivo by use of optical clearing agents," Opt. Express 13, 2337–2344 (2005).

[5] [5] C. A. Combs, A. V. Smirnov, J. D. Riley, A. H. Gandjbakhche, J. R. Knutson, R. S. Balaban, "Optimization of multiphoton excitation microscopy by total emission detection using a parabolic light reflector," J. Microsc. 228, 330–337 (2007).

[6] [6] P. J. Campagnola, C. Dong, "Second harmonic generation microscopy: Principles and applications to disease diagnosis," Laser Photon. Rev. 5(1), 13– 26 (2011).

[7] [7] W. R. Zipfel, R. M. Williams, W. W. Watt, "Nonlinear magic: Multiphoton microscopy in the biosciences," Nat. Biotechnol. 21(11), 1369–1377 (2003).

[8] [8] X. Chen, C. Raggio, P. J. Campagnola, "Secondharmonic generation circular dichroism studies of osteogenesis imperfecta," Opt Lett. 37, 18 (2012).

[9] [9] O. Nadiarnykh, R. B. LaComb, M. A. Brewer, P. J. Campagnola, "Alterations of the extracellular matrix in ovarian cancer studied by second harmonic generation imaging microscopy," BMC Cancer 10, 94 (2010).

[10] [10] V. Ajeti, O. Nadiarnykh, S. M. Ponik, P. J. Keely, K. W. Eliceiri, P. J. Campagnola, "Structural changes in mixed Col I/Col V collagen gels probed by SHG microscopy: Implications for probing stromal alterations in human breast cancer," Biomed. Opt. Express 2(8), 2307–2316 (2011).

[11] [11] S. V. Plotnikov, A. M. Kenny, S. J. Walsh, B. Zubrowski, C. Joseph, V. L. Scranton, G. A. Kuchel, D. Dauser, M. Xu, C. C. Pilbeam, D. J. Adams, R. P. Dougherty, P. J. Campagnola, W. A. Mohler, "Measurement of muscle disease by quantitative second-harmonic generation imaging," J. Biomed. Opt. 13(4) (2008).

[12] [12] H. C. Ishikawa-Ankerhold, R. Ankerhold, G. P. C. Drummen, "Advanced fluorescence microscopy techniques — FRAP, FLIP, FLAP, FRET and FLIM," Molecules 17, 4047–4132 (2012).

[13] [13] P. I. Bastiaens, A. Squire, "Fluorescence lifetime imaging microscopy: Spatial resolution of biochemical processes in the cell," Trends Cell Biol. 9, 48–52 (1999).

[14] [14] E. B. van Munster, T. W. Gadella, Jr., "Suppression of photobleaching-induced artifacts infrequency-domain FLIM by permutation of the recording order," Cytometry A 58, 185–194 (2004).

[15] [15] M. A. Digman, V. R. Caiolfa, M. Zamai, E. Gratton, "The phasor approach to fluorescence lifetime imaging analysis," Biophys J. 94(2), L14–L16 (2008).

[16] [16] V. Crosignani, A. S. Dvornikov, E. Gratton, "Enhancement of imaging depth in turbid media using a wide area detector," J. Biophotonics 4(9), 592–599 (2011).

[17] [17] V. Crosignani, A. S. Dvornikov, J. S. Aguilar, C. Stringari, R. Edwards, W. W. Mantulin, E. Gratton, "Deep tissue fluorescence imaging and in vivo biological applications," J. Biomed. Opt. 17(11), 116023-1–7 (2012).

[18] [18] F. Ayers, A. Grant, D. Kuo, D. J. Cuccia, A. J. Durkin, "Fabrication and characterization of silicone- based tissue phantoms with tunable optical properties in the visible and near infrared domain," Proc. SPIE 6870, 687007-1-9 (2008).

[19] [19] V. Crosignani, A. Dvornikov, E. Gratton "Ultradeep imaging of turbid samples by enhanced photon harvesting," Proc. SPIE 8588, 858810–858811 (2013).

[20] [20] S. Romani, C. Razzetti, M. Zha, C. Paorici, "Evaluation of the effective second harmonic generation coefficient of monomethyl urea single crystals," Phys. Status Solidi (B) 197, 271 (1996).

[21] [21] C. Chang, D. Sud, M. Mycek, "Fluorescence lifetime imaging microscopy," Methods Cell Biol. 81, 495– 524 (2007).