Abstract

Fibered image guides for confocal reflectance endomicroscopy suffer from Fresnel reflections at the fiber terminals, which can limit signal-to-noise ratio in these systems. A model that describes these terminal reflections is presented to better understand how they can be managed most effectively. An expression for the refractive index of termination that minimizes the reflection as a function of the fiber’s normalized frequency is derived for step-index fibers, while a graphical solution is presented for graded-index fibers. The model predicts that terminal reflections from graded-index fibers are more sensitive to variations in fiber size and changes in wavelength than step-index fibers. A method is also presented to measure the refractive index that allows one to minimize the terminal reflections in an image guide. The technique uses the inherent mode coupling of the fibers in the image guide, allowing the isolation and measurement of reflections from only one end of the fiber. An achievable minimum backreflection of 36dB was measured at 635nm in a commercial image guide with 30,000 fibers.

© 2009 Optical Society of America

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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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  24. P. Lane, “Reflection-contrast limit of fiber-optic image guides,” J Biomed. Opt. (to be published).
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    [CrossRef]

2009 (1)

P. M. Lane, S. Lam, A. McWilliams, J. C. Leriche, M. W. Anderson, and C. E. MacAulay, “Confocal fluorescence microendoscopy of bronchial epithelium,” J Biomed. Opt. 14, 024008 (2009).
[CrossRef]

2008 (2)

2007 (3)

K. L. Reichenbach and C. Xu, “Numerical analysis of light propagation in image fibers or coherent fiber bundles,” Opt. Express 15, 2151-2165 (2007).
[CrossRef]

J. A. Udovich, A. R. Rouse, A. Tanbakuchi, M. A. Brewer, R. Sampliner, and A. F. Gmitro, “Confocal microendoscope for use in a clinical setting,” Proc. SPIE 6432, H64320H(2007).

T. Collier, M. Guillaud, M. Follen, A. Malpica, and R. Richards-Kortum, “Real-time reflectance confocal microscopy: comparison of two-dimensional images and three-dimensional image stacks for detection of cervical precancer,” J. Biomed. Opt. 12, 024021 (2007).
[CrossRef]

2006 (1)

E. R. Hsu, A. M. Gillenwater, M. Q. Hasan, M. D. Williams, A. K. El-Naggar, and R. R. Richards-Kortum, “Real-time detection of epidermal growth factor receptor expression in fresh oral cavity biopsies using a molecular-specific contrast agent,” Int. J. Cancer 118, 3062-3071 (2006).
[CrossRef]

2005 (1)

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, “Fiber-optic fluorescence imaging,” Nat. Methods 2, 941-950 (2005).
[CrossRef]

2004 (1)

C. MacAulay, P. Lane, and R. Richards-Kortum, “In vivo pathology: microendoscopy as a new endoscopic imaging modality,” Gastrointest. Endosc. Clin. N. Am. 14, 595-620(2004).
[CrossRef]

2003 (2)

I. Pavlova, K. Sokolov, R. Drezek, A. Malpica, M. Follen, and R. Richards-Kortum, “Microanatomical and biochemical origins of normal and precancerous cervical autofluorescence using laser-scanning fluorescence confocal microscopy,” Photochem. Photobiol. 77, 550-555 (2003).
[CrossRef]

A. L. Clark, A. M. Gillenwater, T. G. Collier, R. Alizadeh-Naderi, A. K. El-Naggar, and R. R. Richards-Kortum, “Confocal microscopy for real-time detection of oral cavity neoplasia,” Clin. Cancer Res. 9, 4714-4721 (2003).

2002 (4)

K. B. Sung, C. N. Liang, M. Descour, T. Collier, M. Follen, and R. Richards-Kortum, “Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues,” IEEE Trans. Biomed. Eng. 49, 1168-1172 (2002).
[CrossRef]

K. B. Sung, C. Liang, M. Descour, T. Collier, M. Follen, A. Malpica, and R. Richards-Kortum, “Near real time in vivo fibre optic confocal microscopy: subcellular structure resolved,” J. Microsc. 208, 75-75 (2002).
[CrossRef]

T. Collier, A. Lacy, R. Richards-Kortum, A. Malpica, and M. Follen, “Near real-time confocal microscopy of amelanotic tissue: detection of dysplasia in ex vivo cervical tissue,” Acad. Radiol. 9, 504-512 (2002).
[CrossRef]

K. Sokolov, K. B. Sung, T. Collier, A. Clark, D. Arifler, A. Lacy, M. Descour, and R. Richards-Kortum, “Endoscopic microscopy,” Dis. Markers 18, 269-291 (2002).

2000 (1)

1999 (2)

1998 (2)

C. Smithpeter, A. Duan, R. Drezek, T. Collier, and R. Richards-Kortum, “Near real time confocal microscopy of cultured amelanotic cells: sources of signal, contrast agents and limits of contrast,” J Biomed. Opt. 3, 429-436 (1998).
[CrossRef]

Y. W. Ma and L. Huang, “The crosstalk study of order-packed flexible image bundles,” Proc. SPIE 3552, 232-237 (1998).
[CrossRef]

1996 (2)

R. Conde, C. Depeursinge, B. Gisin, N. Gisin, and B. Groebli, “Refractive index profile and geometry measurements in multicore fibres,” J. Opt. A Pure Appl. Opt. 5, 269-274 (1996).

A. K. Dunn, C. Smithpeter, A. J. Welch, and R. Richards-Kortum, “Sources of contrast in confocal reflectance imaging,” Appl. Opt. 35, 3441-3446 (1996).
[CrossRef]

1995 (1)

M. Rajadhyaksha, M. Grossman, D. Esterowitz, R. H. Webb, and R. R. Anderson, “In-Vivo confocal scanning laser microscopy of human skin--melanin provides strong contrast,” J. Invest. Dermatol. 104, 946-952 (1995).
[CrossRef]

1993 (1)

Alizadeh-Naderi, R.

A. L. Clark, A. M. Gillenwater, T. G. Collier, R. Alizadeh-Naderi, A. K. El-Naggar, and R. R. Richards-Kortum, “Confocal microscopy for real-time detection of oral cavity neoplasia,” Clin. Cancer Res. 9, 4714-4721 (2003).

Anderson, M. W.

P. M. Lane, S. Lam, A. McWilliams, J. C. Leriche, M. W. Anderson, and C. E. MacAulay, “Confocal fluorescence microendoscopy of bronchial epithelium,” J Biomed. Opt. 14, 024008 (2009).
[CrossRef]

Anderson, R. R.

M. Rajadhyaksha, M. Grossman, D. Esterowitz, R. H. Webb, and R. R. Anderson, “In-Vivo confocal scanning laser microscopy of human skin--melanin provides strong contrast,” J. Invest. Dermatol. 104, 946-952 (1995).
[CrossRef]

Arifler, D.

K. Sokolov, K. B. Sung, T. Collier, A. Clark, D. Arifler, A. Lacy, M. Descour, and R. Richards-Kortum, “Endoscopic microscopy,” Dis. Markers 18, 269-291 (2002).

Aziz, D.

Brewer, M. A.

J. A. Udovich, A. R. Rouse, A. Tanbakuchi, M. A. Brewer, R. Sampliner, and A. F. Gmitro, “Confocal microendoscope for use in a clinical setting,” Proc. SPIE 6432, H64320H(2007).

Chen, X. P.

Cheung, E. L. M.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, “Fiber-optic fluorescence imaging,” Nat. Methods 2, 941-950 (2005).
[CrossRef]

Clark, A.

K. Sokolov, K. B. Sung, T. Collier, A. Clark, D. Arifler, A. Lacy, M. Descour, and R. Richards-Kortum, “Endoscopic microscopy,” Dis. Markers 18, 269-291 (2002).

Clark, A. L.

A. L. Clark, A. M. Gillenwater, T. G. Collier, R. Alizadeh-Naderi, A. K. El-Naggar, and R. R. Richards-Kortum, “Confocal microscopy for real-time detection of oral cavity neoplasia,” Clin. Cancer Res. 9, 4714-4721 (2003).

Cocker, E. D.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, “Fiber-optic fluorescence imaging,” Nat. Methods 2, 941-950 (2005).
[CrossRef]

Collier, T.

T. Collier, M. Guillaud, M. Follen, A. Malpica, and R. Richards-Kortum, “Real-time reflectance confocal microscopy: comparison of two-dimensional images and three-dimensional image stacks for detection of cervical precancer,” J. Biomed. Opt. 12, 024021 (2007).
[CrossRef]

T. Collier, A. Lacy, R. Richards-Kortum, A. Malpica, and M. Follen, “Near real-time confocal microscopy of amelanotic tissue: detection of dysplasia in ex vivo cervical tissue,” Acad. Radiol. 9, 504-512 (2002).
[CrossRef]

K. Sokolov, K. B. Sung, T. Collier, A. Clark, D. Arifler, A. Lacy, M. Descour, and R. Richards-Kortum, “Endoscopic microscopy,” Dis. Markers 18, 269-291 (2002).

K. B. Sung, C. N. Liang, M. Descour, T. Collier, M. Follen, and R. Richards-Kortum, “Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues,” IEEE Trans. Biomed. Eng. 49, 1168-1172 (2002).
[CrossRef]

K. B. Sung, C. Liang, M. Descour, T. Collier, M. Follen, A. Malpica, and R. Richards-Kortum, “Near real time in vivo fibre optic confocal microscopy: subcellular structure resolved,” J. Microsc. 208, 75-75 (2002).
[CrossRef]

C. Smithpeter, A. Duan, R. Drezek, T. Collier, and R. Richards-Kortum, “Near real time confocal microscopy of cultured amelanotic cells: sources of signal, contrast agents and limits of contrast,” J Biomed. Opt. 3, 429-436 (1998).
[CrossRef]

Collier, T. G.

A. L. Clark, A. M. Gillenwater, T. G. Collier, R. Alizadeh-Naderi, A. K. El-Naggar, and R. R. Richards-Kortum, “Confocal microscopy for real-time detection of oral cavity neoplasia,” Clin. Cancer Res. 9, 4714-4721 (2003).

Conde, R.

R. Conde, C. Depeursinge, B. Gisin, N. Gisin, and B. Groebli, “Refractive index profile and geometry measurements in multicore fibres,” J. Opt. A Pure Appl. Opt. 5, 269-274 (1996).

Depeursinge, C.

R. Conde, C. Depeursinge, B. Gisin, N. Gisin, and B. Groebli, “Refractive index profile and geometry measurements in multicore fibres,” J. Opt. A Pure Appl. Opt. 5, 269-274 (1996).

Descour, M.

K. B. Sung, C. N. Liang, M. Descour, T. Collier, M. Follen, and R. Richards-Kortum, “Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues,” IEEE Trans. Biomed. Eng. 49, 1168-1172 (2002).
[CrossRef]

K. B. Sung, C. Liang, M. Descour, T. Collier, M. Follen, A. Malpica, and R. Richards-Kortum, “Near real time in vivo fibre optic confocal microscopy: subcellular structure resolved,” J. Microsc. 208, 75-75 (2002).
[CrossRef]

K. Sokolov, K. B. Sung, T. Collier, A. Clark, D. Arifler, A. Lacy, M. Descour, and R. Richards-Kortum, “Endoscopic microscopy,” Dis. Markers 18, 269-291 (2002).

Dlugan, A. L. P.

Donaldson, L.

Drezek, R.

I. Pavlova, K. Sokolov, R. Drezek, A. Malpica, M. Follen, and R. Richards-Kortum, “Microanatomical and biochemical origins of normal and precancerous cervical autofluorescence using laser-scanning fluorescence confocal microscopy,” Photochem. Photobiol. 77, 550-555 (2003).
[CrossRef]

R. Drezek, A. Dunn, and R. Richards-Kortum, “Light scattering from cells: finite-difference time-domain simulations and goniometric measurements,” Appl. Opt. 38, 3651-3661(1999).
[CrossRef]

C. Smithpeter, A. Duan, R. Drezek, T. Collier, and R. Richards-Kortum, “Near real time confocal microscopy of cultured amelanotic cells: sources of signal, contrast agents and limits of contrast,” J Biomed. Opt. 3, 429-436 (1998).
[CrossRef]

Duan, A.

C. Smithpeter, A. Duan, R. Drezek, T. Collier, and R. Richards-Kortum, “Near real time confocal microscopy of cultured amelanotic cells: sources of signal, contrast agents and limits of contrast,” J Biomed. Opt. 3, 429-436 (1998).
[CrossRef]

Dunn, A.

Dunn, A. K.

El-Naggar, A. K.

E. R. Hsu, A. M. Gillenwater, M. Q. Hasan, M. D. Williams, A. K. El-Naggar, and R. R. Richards-Kortum, “Real-time detection of epidermal growth factor receptor expression in fresh oral cavity biopsies using a molecular-specific contrast agent,” Int. J. Cancer 118, 3062-3071 (2006).
[CrossRef]

A. L. Clark, A. M. Gillenwater, T. G. Collier, R. Alizadeh-Naderi, A. K. El-Naggar, and R. R. Richards-Kortum, “Confocal microscopy for real-time detection of oral cavity neoplasia,” Clin. Cancer Res. 9, 4714-4721 (2003).

Esterowitz, D.

M. Rajadhyaksha, M. Grossman, D. Esterowitz, R. H. Webb, and R. R. Anderson, “In-Vivo confocal scanning laser microscopy of human skin--melanin provides strong contrast,” J. Invest. Dermatol. 104, 946-952 (1995).
[CrossRef]

Flusberg, B. A.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, “Fiber-optic fluorescence imaging,” Nat. Methods 2, 941-950 (2005).
[CrossRef]

Follen, M.

T. Collier, M. Guillaud, M. Follen, A. Malpica, and R. Richards-Kortum, “Real-time reflectance confocal microscopy: comparison of two-dimensional images and three-dimensional image stacks for detection of cervical precancer,” J. Biomed. Opt. 12, 024021 (2007).
[CrossRef]

I. Pavlova, K. Sokolov, R. Drezek, A. Malpica, M. Follen, and R. Richards-Kortum, “Microanatomical and biochemical origins of normal and precancerous cervical autofluorescence using laser-scanning fluorescence confocal microscopy,” Photochem. Photobiol. 77, 550-555 (2003).
[CrossRef]

T. Collier, A. Lacy, R. Richards-Kortum, A. Malpica, and M. Follen, “Near real-time confocal microscopy of amelanotic tissue: detection of dysplasia in ex vivo cervical tissue,” Acad. Radiol. 9, 504-512 (2002).
[CrossRef]

K. B. Sung, C. Liang, M. Descour, T. Collier, M. Follen, A. Malpica, and R. Richards-Kortum, “Near real time in vivo fibre optic confocal microscopy: subcellular structure resolved,” J. Microsc. 208, 75-75 (2002).
[CrossRef]

K. B. Sung, C. N. Liang, M. Descour, T. Collier, M. Follen, and R. Richards-Kortum, “Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues,” IEEE Trans. Biomed. Eng. 49, 1168-1172 (2002).
[CrossRef]

Gillenwater, A. M.

E. R. Hsu, A. M. Gillenwater, M. Q. Hasan, M. D. Williams, A. K. El-Naggar, and R. R. Richards-Kortum, “Real-time detection of epidermal growth factor receptor expression in fresh oral cavity biopsies using a molecular-specific contrast agent,” Int. J. Cancer 118, 3062-3071 (2006).
[CrossRef]

A. L. Clark, A. M. Gillenwater, T. G. Collier, R. Alizadeh-Naderi, A. K. El-Naggar, and R. R. Richards-Kortum, “Confocal microscopy for real-time detection of oral cavity neoplasia,” Clin. Cancer Res. 9, 4714-4721 (2003).

Gisin, B.

R. Conde, C. Depeursinge, B. Gisin, N. Gisin, and B. Groebli, “Refractive index profile and geometry measurements in multicore fibres,” J. Opt. A Pure Appl. Opt. 5, 269-274 (1996).

Gisin, N.

R. Conde, C. Depeursinge, B. Gisin, N. Gisin, and B. Groebli, “Refractive index profile and geometry measurements in multicore fibres,” J. Opt. A Pure Appl. Opt. 5, 269-274 (1996).

Gmitro, A. F.

Groebli, B.

R. Conde, C. Depeursinge, B. Gisin, N. Gisin, and B. Groebli, “Refractive index profile and geometry measurements in multicore fibres,” J. Opt. A Pure Appl. Opt. 5, 269-274 (1996).

Grossman, M.

M. Rajadhyaksha, M. Grossman, D. Esterowitz, R. H. Webb, and R. R. Anderson, “In-Vivo confocal scanning laser microscopy of human skin--melanin provides strong contrast,” J. Invest. Dermatol. 104, 946-952 (1995).
[CrossRef]

Guillaud, M.

T. Collier, M. Guillaud, M. Follen, A. Malpica, and R. Richards-Kortum, “Real-time reflectance confocal microscopy: comparison of two-dimensional images and three-dimensional image stacks for detection of cervical precancer,” J. Biomed. Opt. 12, 024021 (2007).
[CrossRef]

Hasan, M. Q.

E. R. Hsu, A. M. Gillenwater, M. Q. Hasan, M. D. Williams, A. K. El-Naggar, and R. R. Richards-Kortum, “Real-time detection of epidermal growth factor receptor expression in fresh oral cavity biopsies using a molecular-specific contrast agent,” Int. J. Cancer 118, 3062-3071 (2006).
[CrossRef]

Hopkins, M. F.

Hsu, E. R.

E. R. Hsu, A. M. Gillenwater, M. Q. Hasan, M. D. Williams, A. K. El-Naggar, and R. R. Richards-Kortum, “Real-time detection of epidermal growth factor receptor expression in fresh oral cavity biopsies using a molecular-specific contrast agent,” Int. J. Cancer 118, 3062-3071 (2006).
[CrossRef]

Huang, L.

Y. W. Ma and L. Huang, “The crosstalk study of order-packed flexible image bundles,” Proc. SPIE 3552, 232-237 (1998).
[CrossRef]

Jung, J. C.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, “Fiber-optic fluorescence imaging,” Nat. Methods 2, 941-950 (2005).
[CrossRef]

Kano, A.

Kirkpatrick, N. D.

Kuwamura, N.

N. Kuwamura, Sumitomo Electric USA, Inc. (personal communication, 2009).

Lacy, A.

K. Sokolov, K. B. Sung, T. Collier, A. Clark, D. Arifler, A. Lacy, M. Descour, and R. Richards-Kortum, “Endoscopic microscopy,” Dis. Markers 18, 269-291 (2002).

T. Collier, A. Lacy, R. Richards-Kortum, A. Malpica, and M. Follen, “Near real-time confocal microscopy of amelanotic tissue: detection of dysplasia in ex vivo cervical tissue,” Acad. Radiol. 9, 504-512 (2002).
[CrossRef]

Lam, S.

P. M. Lane, S. Lam, A. McWilliams, J. C. Leriche, M. W. Anderson, and C. E. MacAulay, “Confocal fluorescence microendoscopy of bronchial epithelium,” J Biomed. Opt. 14, 024008 (2009).
[CrossRef]

Lane, P.

C. MacAulay, P. Lane, and R. Richards-Kortum, “In vivo pathology: microendoscopy as a new endoscopic imaging modality,” Gastrointest. Endosc. Clin. N. Am. 14, 595-620(2004).
[CrossRef]

P. Lane, “Reflection-contrast limit of fiber-optic image guides,” J Biomed. Opt. (to be published).

Lane, P. M.

P. M. Lane, S. Lam, A. McWilliams, J. C. Leriche, M. W. Anderson, and C. E. MacAulay, “Confocal fluorescence microendoscopy of bronchial epithelium,” J Biomed. Opt. 14, 024008 (2009).
[CrossRef]

P. M. Lane, A. L. P. Dlugan, R. Richards-Kortum, and C. E. MacAulay, “Fiber-optic confocal microscopy using a spatial light modulator,” Opt. Lett. 25, 1780-1782 (2000).
[CrossRef]

Leriche, J. C.

P. M. Lane, S. Lam, A. McWilliams, J. C. Leriche, M. W. Anderson, and C. E. MacAulay, “Confocal fluorescence microendoscopy of bronchial epithelium,” J Biomed. Opt. 14, 024008 (2009).
[CrossRef]

Liang, C.

K. B. Sung, C. Liang, M. Descour, T. Collier, M. Follen, A. Malpica, and R. Richards-Kortum, “Near real time in vivo fibre optic confocal microscopy: subcellular structure resolved,” J. Microsc. 208, 75-75 (2002).
[CrossRef]

Liang, C. N.

K. B. Sung, C. N. Liang, M. Descour, T. Collier, M. Follen, and R. Richards-Kortum, “Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues,” IEEE Trans. Biomed. Eng. 49, 1168-1172 (2002).
[CrossRef]

Love, J. D.

A. W. Snyder and J. D. Love, Optical Waveguide Theory (Chapman and Hall, 1983).

Ma, Y. W.

Y. W. Ma and L. Huang, “The crosstalk study of order-packed flexible image bundles,” Proc. SPIE 3552, 232-237 (1998).
[CrossRef]

MacAulay, C.

C. MacAulay, P. Lane, and R. Richards-Kortum, “In vivo pathology: microendoscopy as a new endoscopic imaging modality,” Gastrointest. Endosc. Clin. N. Am. 14, 595-620(2004).
[CrossRef]

MacAulay, C. E.

P. M. Lane, S. Lam, A. McWilliams, J. C. Leriche, M. W. Anderson, and C. E. MacAulay, “Confocal fluorescence microendoscopy of bronchial epithelium,” J Biomed. Opt. 14, 024008 (2009).
[CrossRef]

P. M. Lane, A. L. P. Dlugan, R. Richards-Kortum, and C. E. MacAulay, “Fiber-optic confocal microscopy using a spatial light modulator,” Opt. Lett. 25, 1780-1782 (2000).
[CrossRef]

Malpica, A.

T. Collier, M. Guillaud, M. Follen, A. Malpica, and R. Richards-Kortum, “Real-time reflectance confocal microscopy: comparison of two-dimensional images and three-dimensional image stacks for detection of cervical precancer,” J. Biomed. Opt. 12, 024021 (2007).
[CrossRef]

I. Pavlova, K. Sokolov, R. Drezek, A. Malpica, M. Follen, and R. Richards-Kortum, “Microanatomical and biochemical origins of normal and precancerous cervical autofluorescence using laser-scanning fluorescence confocal microscopy,” Photochem. Photobiol. 77, 550-555 (2003).
[CrossRef]

T. Collier, A. Lacy, R. Richards-Kortum, A. Malpica, and M. Follen, “Near real-time confocal microscopy of amelanotic tissue: detection of dysplasia in ex vivo cervical tissue,” Acad. Radiol. 9, 504-512 (2002).
[CrossRef]

K. B. Sung, C. Liang, M. Descour, T. Collier, M. Follen, A. Malpica, and R. Richards-Kortum, “Near real time in vivo fibre optic confocal microscopy: subcellular structure resolved,” J. Microsc. 208, 75-75 (2002).
[CrossRef]

McWilliams, A.

P. M. Lane, S. Lam, A. McWilliams, J. C. Leriche, M. W. Anderson, and C. E. MacAulay, “Confocal fluorescence microendoscopy of bronchial epithelium,” J Biomed. Opt. 14, 024008 (2009).
[CrossRef]

Pavlova, I.

I. Pavlova, K. Sokolov, R. Drezek, A. Malpica, M. Follen, and R. Richards-Kortum, “Microanatomical and biochemical origins of normal and precancerous cervical autofluorescence using laser-scanning fluorescence confocal microscopy,” Photochem. Photobiol. 77, 550-555 (2003).
[CrossRef]

Piyawattanametha, W.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, “Fiber-optic fluorescence imaging,” Nat. Methods 2, 941-950 (2005).
[CrossRef]

Rajadhyaksha, M.

M. Rajadhyaksha, M. Grossman, D. Esterowitz, R. H. Webb, and R. R. Anderson, “In-Vivo confocal scanning laser microscopy of human skin--melanin provides strong contrast,” J. Invest. Dermatol. 104, 946-952 (1995).
[CrossRef]

Reichenbach, K. L.

Richards-Kortum, R.

T. Collier, M. Guillaud, M. Follen, A. Malpica, and R. Richards-Kortum, “Real-time reflectance confocal microscopy: comparison of two-dimensional images and three-dimensional image stacks for detection of cervical precancer,” J. Biomed. Opt. 12, 024021 (2007).
[CrossRef]

C. MacAulay, P. Lane, and R. Richards-Kortum, “In vivo pathology: microendoscopy as a new endoscopic imaging modality,” Gastrointest. Endosc. Clin. N. Am. 14, 595-620(2004).
[CrossRef]

I. Pavlova, K. Sokolov, R. Drezek, A. Malpica, M. Follen, and R. Richards-Kortum, “Microanatomical and biochemical origins of normal and precancerous cervical autofluorescence using laser-scanning fluorescence confocal microscopy,” Photochem. Photobiol. 77, 550-555 (2003).
[CrossRef]

T. Collier, A. Lacy, R. Richards-Kortum, A. Malpica, and M. Follen, “Near real-time confocal microscopy of amelanotic tissue: detection of dysplasia in ex vivo cervical tissue,” Acad. Radiol. 9, 504-512 (2002).
[CrossRef]

K. Sokolov, K. B. Sung, T. Collier, A. Clark, D. Arifler, A. Lacy, M. Descour, and R. Richards-Kortum, “Endoscopic microscopy,” Dis. Markers 18, 269-291 (2002).

K. B. Sung, C. Liang, M. Descour, T. Collier, M. Follen, A. Malpica, and R. Richards-Kortum, “Near real time in vivo fibre optic confocal microscopy: subcellular structure resolved,” J. Microsc. 208, 75-75 (2002).
[CrossRef]

K. B. Sung, C. N. Liang, M. Descour, T. Collier, M. Follen, and R. Richards-Kortum, “Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues,” IEEE Trans. Biomed. Eng. 49, 1168-1172 (2002).
[CrossRef]

P. M. Lane, A. L. P. Dlugan, R. Richards-Kortum, and C. E. MacAulay, “Fiber-optic confocal microscopy using a spatial light modulator,” Opt. Lett. 25, 1780-1782 (2000).
[CrossRef]

R. Drezek, A. Dunn, and R. Richards-Kortum, “Light scattering from cells: finite-difference time-domain simulations and goniometric measurements,” Appl. Opt. 38, 3651-3661(1999).
[CrossRef]

C. Smithpeter, A. Duan, R. Drezek, T. Collier, and R. Richards-Kortum, “Near real time confocal microscopy of cultured amelanotic cells: sources of signal, contrast agents and limits of contrast,” J Biomed. Opt. 3, 429-436 (1998).
[CrossRef]

A. K. Dunn, C. Smithpeter, A. J. Welch, and R. Richards-Kortum, “Sources of contrast in confocal reflectance imaging,” Appl. Opt. 35, 3441-3446 (1996).
[CrossRef]

Richards-Kortum, R. R.

E. R. Hsu, A. M. Gillenwater, M. Q. Hasan, M. D. Williams, A. K. El-Naggar, and R. R. Richards-Kortum, “Real-time detection of epidermal growth factor receptor expression in fresh oral cavity biopsies using a molecular-specific contrast agent,” Int. J. Cancer 118, 3062-3071 (2006).
[CrossRef]

A. L. Clark, A. M. Gillenwater, T. G. Collier, R. Alizadeh-Naderi, A. K. El-Naggar, and R. R. Richards-Kortum, “Confocal microscopy for real-time detection of oral cavity neoplasia,” Clin. Cancer Res. 9, 4714-4721 (2003).

Rouse, A. R.

J. A. Udovich, A. R. Rouse, A. Tanbakuchi, M. A. Brewer, R. Sampliner, and A. F. Gmitro, “Confocal microendoscope for use in a clinical setting,” Proc. SPIE 6432, H64320H(2007).

Y. S. Sabharwal, A. R. Rouse, L. Donaldson, M. F. Hopkins, and A. F. Gmitro, “Slit-scanning confocal microendoscope for high-resolution in vivo imaging,” Appl. Opt. 38, 7133-7144(1999).
[CrossRef]

Sabharwal, Y. S.

Sampliner, R.

J. A. Udovich, A. R. Rouse, A. Tanbakuchi, M. A. Brewer, R. Sampliner, and A. F. Gmitro, “Confocal microendoscope for use in a clinical setting,” Proc. SPIE 6432, H64320H(2007).

Schnitzer, M. J.

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, “Fiber-optic fluorescence imaging,” Nat. Methods 2, 941-950 (2005).
[CrossRef]

Smithpeter, C.

C. Smithpeter, A. Duan, R. Drezek, T. Collier, and R. Richards-Kortum, “Near real time confocal microscopy of cultured amelanotic cells: sources of signal, contrast agents and limits of contrast,” J Biomed. Opt. 3, 429-436 (1998).
[CrossRef]

A. K. Dunn, C. Smithpeter, A. J. Welch, and R. Richards-Kortum, “Sources of contrast in confocal reflectance imaging,” Appl. Opt. 35, 3441-3446 (1996).
[CrossRef]

Snyder, A. W.

A. W. Snyder and J. D. Love, Optical Waveguide Theory (Chapman and Hall, 1983).

Sokolov, K.

I. Pavlova, K. Sokolov, R. Drezek, A. Malpica, M. Follen, and R. Richards-Kortum, “Microanatomical and biochemical origins of normal and precancerous cervical autofluorescence using laser-scanning fluorescence confocal microscopy,” Photochem. Photobiol. 77, 550-555 (2003).
[CrossRef]

K. Sokolov, K. B. Sung, T. Collier, A. Clark, D. Arifler, A. Lacy, M. Descour, and R. Richards-Kortum, “Endoscopic microscopy,” Dis. Markers 18, 269-291 (2002).

Sung, K. B.

K. Sokolov, K. B. Sung, T. Collier, A. Clark, D. Arifler, A. Lacy, M. Descour, and R. Richards-Kortum, “Endoscopic microscopy,” Dis. Markers 18, 269-291 (2002).

K. B. Sung, C. Liang, M. Descour, T. Collier, M. Follen, A. Malpica, and R. Richards-Kortum, “Near real time in vivo fibre optic confocal microscopy: subcellular structure resolved,” J. Microsc. 208, 75-75 (2002).
[CrossRef]

K. B. Sung, C. N. Liang, M. Descour, T. Collier, M. Follen, and R. Richards-Kortum, “Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues,” IEEE Trans. Biomed. Eng. 49, 1168-1172 (2002).
[CrossRef]

Tanbakuchi, A.

J. A. Udovich, N. D. Kirkpatrick, A. Kano, A. Tanbakuchi, U. Utzinger, and A. F. Gmitro, “Spectral background and transmission characteristics of fiber optic imaging bundles,” Appl. Opt. 47, 4560-4568 (2008).
[CrossRef]

J. A. Udovich, A. R. Rouse, A. Tanbakuchi, M. A. Brewer, R. Sampliner, and A. F. Gmitro, “Confocal microendoscope for use in a clinical setting,” Proc. SPIE 6432, H64320H(2007).

Udovich, J. A.

J. A. Udovich, N. D. Kirkpatrick, A. Kano, A. Tanbakuchi, U. Utzinger, and A. F. Gmitro, “Spectral background and transmission characteristics of fiber optic imaging bundles,” Appl. Opt. 47, 4560-4568 (2008).
[CrossRef]

J. A. Udovich, A. R. Rouse, A. Tanbakuchi, M. A. Brewer, R. Sampliner, and A. F. Gmitro, “Confocal microendoscope for use in a clinical setting,” Proc. SPIE 6432, H64320H(2007).

Utzinger, U.

Webb, R. H.

M. Rajadhyaksha, M. Grossman, D. Esterowitz, R. H. Webb, and R. R. Anderson, “In-Vivo confocal scanning laser microscopy of human skin--melanin provides strong contrast,” J. Invest. Dermatol. 104, 946-952 (1995).
[CrossRef]

Welch, A. J.

Williams, M. D.

E. R. Hsu, A. M. Gillenwater, M. Q. Hasan, M. D. Williams, A. K. El-Naggar, and R. R. Richards-Kortum, “Real-time detection of epidermal growth factor receptor expression in fresh oral cavity biopsies using a molecular-specific contrast agent,” Int. J. Cancer 118, 3062-3071 (2006).
[CrossRef]

Xu, C.

Acad. Radiol. (1)

T. Collier, A. Lacy, R. Richards-Kortum, A. Malpica, and M. Follen, “Near real-time confocal microscopy of amelanotic tissue: detection of dysplasia in ex vivo cervical tissue,” Acad. Radiol. 9, 504-512 (2002).
[CrossRef]

Appl. Opt. (4)

Clin. Cancer Res. (1)

A. L. Clark, A. M. Gillenwater, T. G. Collier, R. Alizadeh-Naderi, A. K. El-Naggar, and R. R. Richards-Kortum, “Confocal microscopy for real-time detection of oral cavity neoplasia,” Clin. Cancer Res. 9, 4714-4721 (2003).

Dis. Markers (1)

K. Sokolov, K. B. Sung, T. Collier, A. Clark, D. Arifler, A. Lacy, M. Descour, and R. Richards-Kortum, “Endoscopic microscopy,” Dis. Markers 18, 269-291 (2002).

Gastrointest. Endosc. Clin. N. Am. (1)

C. MacAulay, P. Lane, and R. Richards-Kortum, “In vivo pathology: microendoscopy as a new endoscopic imaging modality,” Gastrointest. Endosc. Clin. N. Am. 14, 595-620(2004).
[CrossRef]

IEEE Trans. Biomed. Eng. (1)

K. B. Sung, C. N. Liang, M. Descour, T. Collier, M. Follen, and R. Richards-Kortum, “Fiber-optic confocal reflectance microscope with miniature objective for in vivo imaging of human tissues,” IEEE Trans. Biomed. Eng. 49, 1168-1172 (2002).
[CrossRef]

Int. J. Cancer (1)

E. R. Hsu, A. M. Gillenwater, M. Q. Hasan, M. D. Williams, A. K. El-Naggar, and R. R. Richards-Kortum, “Real-time detection of epidermal growth factor receptor expression in fresh oral cavity biopsies using a molecular-specific contrast agent,” Int. J. Cancer 118, 3062-3071 (2006).
[CrossRef]

J Biomed. Opt. (3)

P. M. Lane, S. Lam, A. McWilliams, J. C. Leriche, M. W. Anderson, and C. E. MacAulay, “Confocal fluorescence microendoscopy of bronchial epithelium,” J Biomed. Opt. 14, 024008 (2009).
[CrossRef]

P. Lane, “Reflection-contrast limit of fiber-optic image guides,” J Biomed. Opt. (to be published).

C. Smithpeter, A. Duan, R. Drezek, T. Collier, and R. Richards-Kortum, “Near real time confocal microscopy of cultured amelanotic cells: sources of signal, contrast agents and limits of contrast,” J Biomed. Opt. 3, 429-436 (1998).
[CrossRef]

J. Biomed. Opt. (1)

T. Collier, M. Guillaud, M. Follen, A. Malpica, and R. Richards-Kortum, “Real-time reflectance confocal microscopy: comparison of two-dimensional images and three-dimensional image stacks for detection of cervical precancer,” J. Biomed. Opt. 12, 024021 (2007).
[CrossRef]

J. Invest. Dermatol. (1)

M. Rajadhyaksha, M. Grossman, D. Esterowitz, R. H. Webb, and R. R. Anderson, “In-Vivo confocal scanning laser microscopy of human skin--melanin provides strong contrast,” J. Invest. Dermatol. 104, 946-952 (1995).
[CrossRef]

J. Microsc. (1)

K. B. Sung, C. Liang, M. Descour, T. Collier, M. Follen, A. Malpica, and R. Richards-Kortum, “Near real time in vivo fibre optic confocal microscopy: subcellular structure resolved,” J. Microsc. 208, 75-75 (2002).
[CrossRef]

J. Opt. A Pure Appl. Opt. (1)

R. Conde, C. Depeursinge, B. Gisin, N. Gisin, and B. Groebli, “Refractive index profile and geometry measurements in multicore fibres,” J. Opt. A Pure Appl. Opt. 5, 269-274 (1996).

Nat. Methods (1)

B. A. Flusberg, E. D. Cocker, W. Piyawattanametha, J. C. Jung, E. L. M. Cheung, and M. J. Schnitzer, “Fiber-optic fluorescence imaging,” Nat. Methods 2, 941-950 (2005).
[CrossRef]

Opt. Express (2)

Opt. Lett. (2)

Photochem. Photobiol. (1)

I. Pavlova, K. Sokolov, R. Drezek, A. Malpica, M. Follen, and R. Richards-Kortum, “Microanatomical and biochemical origins of normal and precancerous cervical autofluorescence using laser-scanning fluorescence confocal microscopy,” Photochem. Photobiol. 77, 550-555 (2003).
[CrossRef]

Proc. SPIE (2)

J. A. Udovich, A. R. Rouse, A. Tanbakuchi, M. A. Brewer, R. Sampliner, and A. F. Gmitro, “Confocal microendoscope for use in a clinical setting,” Proc. SPIE 6432, H64320H(2007).

Y. W. Ma and L. Huang, “The crosstalk study of order-packed flexible image bundles,” Proc. SPIE 3552, 232-237 (1998).
[CrossRef]

Other (2)

A. W. Snyder and J. D. Love, Optical Waveguide Theory (Chapman and Hall, 1983).

N. Kuwamura, Sumitomo Electric USA, Inc. (personal communication, 2009).

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Figures (9)

Fig. 1
Fig. 1

Terminal backreflections from a fiber-optic image guide terminated with oils of different RI, n 0 . The image guide (Schott LB5567) has step-index fibers hexagonally packed with an 8.5 μm center-to-center pitch. The terminal RI matches that of the cladding at n 0 = 1.49 (top left, *) and that of the core at n 0 = 1.62 (bottom row, **).

Fig. 2
Fig. 2

Schematic illustrating the symbols used in the termination model. The terminal RI, n 0 , is constant while the RI in each fiber, n ( r ) , has radial dependence parameterized by the core RI, n 1 , and cladding RI, n 2 .

Fig. 3
Fig. 3

Normalized RI and reflectance as a function of normalized radius for a graded-index fiber with a Gaussian RI profile. The normalized terminal RI is N 0 .

Fig. 4
Fig. 4

Incident and reflected field amplitudes as a function of normalized radius for a graded-index fiber with a Gaussian RI profile and a terminal reflective index of N 0 = 0.995 . When R > R 0 , the incident wave function undergoes an external reflection and experiences a phase shift on reflection.

Fig. 5
Fig. 5

Terminal reflections as a function of normalized terminal RI for different normalized frequencies. At large normalized frequencies, the fundamental mode is tightly confined and the terminal RI that minimizes the terminal reflection is equal to the core RI ( N 0 = 1 ).

Fig. 6
Fig. 6

Normalized terminal refractive indices required to minimize the backreflection and normalized spot size versus normalized frequency. The shaded region indicates the normalized frequency of an image guide with 3 μm diameter cores operating in wavelength ranges from 400 nm ( V = 1.8 ) to 2 μm ( V = 8.9 ). Single-mode cutoff is at V = 2.405 , and the dashed line shows the conditions for minimum terminal reflection at 635 nm . The normalized terminal RI required to minimize the terminal backreflection for a step-index fiber is shown for comparison (dashed curve).

Fig. 7
Fig. 7

Schematic illustration of mode coupling between two fibers in an optical image guide: (a) Light coupled into fiber 1 from the microscope objective lens is partially coupled into fiber 2 due to mode coupling along the length of the fiber. Light measured from fiber 2 is due to a reflection from the distal end only. (b) Image intensity distributions measured from fibers 1 and 2.

Fig. 8
Fig. 8

Schematic illustration of the experimental setup used to measure terminal reflection as a function of terminal RI: microscope (MS), laser diode (LD), tube lens (TL), single-mode (SM), charge coupled device (CCD).

Fig. 9
Fig. 9

Measured terminal reflectance versus terminal RI for two different fiber-optic image guides: Reflectance data from (a) a single fiber core from the first image guide and (b) two fiber cores in the same image guide. The curves are nonlinear least-squares fits to the data points, and the best-fit parameters are indicated.

Tables (1)

Tables Icon

Table 1 Nonlinear Least-Squares Fit Results a

Equations (16)

Equations on this page are rendered with MathJax. Learn more.

U 1 ( r ) = I 0 exp ( r 2 w 0 2 ) ,
U 2 ( r ) = r [ n ( r a ) , n 0 ] U 1 ( r ) ,
r ( η 1 , η 2 ) = η 1 η 2 η 1 + η 2 ,
( n 0 ) = term ( U 1 , U 2 ) η ( U 1 , U 2 ) ,
term ( U 1 , U 2 ) = 0 | U 2 ( r ) | 2 r d r 0 | U 1 ( r ) | 2 r d r ,
η ( U 1 , U 2 ) = | 0 U 1 ( r ) U ¯ 2 ( r ) r d r | 2 0 | U 1 ( r ) | 2 r d r 0 | U 2 ( r ) | 2 r d r ,
( n 0 ) = ( 2 w 0 ) 4 [ 0 exp ( 2 r 2 w 0 2 ) n 0 n ( r a ) n 0 + n ( r a ) r d r ] 2 .
n ( R ) = { n 1 , r 1 ( core ) n 2 , r > 1 ( clad ) ,
W 0 = ( ln V ) 1 2 ,
step ( n 0 ) = 1 V 4 [ ( n 2 n 0 n 2 + n 0 ) 2 + ( V 2 1 ) 2 ( n 2 n 0 n 2 + n 0 ) 2 ] .
N 0 step = 1 Δ 2 2 V 2 + V 4 ,
n ( R ) = n 1 1 2 Δ [ 1 exp ( R 2 ) ] .
W 0 = 2 V 1 .
Gauss ( n 0 ) = 4 ( V 1 ) 2 [ 0 exp [ ( V 1 ) R 2 ] r ( R ) R d R ] 2 ,
r ( R ) = N ( R ) N 0 n ( R ) + N 0
12 ( n 0 ) = I 2 r I 1 = 2 κ 12 [ ( n eff n 0 n eff + n 0 ) 2 + 0 ] .

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