Abstract

We report a novel grid based Optofluidic Microscope (OFM) method where a closely spaced 2D grid of nanoapertures (diameter =100 nm, separation =2.5 µm) provided patterned illumination. We achieved a one-to-one mapping of the light transmissions through the nanoapertures onto a high-speed CCD camera. By optically tweezing a targeted sample across the grid in a controlled fashion and recording the time varying light reception from the nanoapertures, we were able to generate high-resolution images of the sample. The achievable resolution limit of the prototype was ~110 nm (Sparrow’s criterion) under optimal conditions. We demonstrated the technique by imaging polystyrene beads and pollen spores.

© 2007 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, "Optofluidic microscopy- a method for implementing a high resolution optical microscope on a chip," Lab Chip 6,1274 - 1276 (2006).
    [CrossRef] [PubMed]
  2. X. Q. Cui, X. Heng, W. W. Zhong, P. W. Sternberg, D. Psaltis, and C. H. Yang, "Imaging microorganisms with a high-resolution on-chip optofluidic microscope," submitted (2007).
  3. B. Hecht, B. Sick, U. P. Wild, V. Deckert, R. Zenobi, O. J. F. Martin, and D. W. Pohl, "Scanning near-field optical microscopy with aperture probes: Fundamentals and applications," J. Chem. Phys. 112, 7761-7774 (2000).
    [CrossRef]
  4. D. Courjon, Near-field microscopy and near-field optics (London: Imperial College Press, 2003).
  5. A. Ashkin, J. M. Dziedzic, J. E. Bjorkholm, and S. Chu, "Observation of a single beam gradient force optical trap for dielectric particles," Opt. Lett. 11, 288-290 (1986).
    [CrossRef] [PubMed]
  6. J. Enger, M. Goksor, K. Ramser, P. Hagberg, and D. Hanstorp, "Optical tweezers applied to a microfluidic system," Lab Chip 4,196-200 (2004).
    [CrossRef] [PubMed]
  7. A. Ashkin, "Forces of a single-beam gradient laser trap on a dielectric sphere in the ray optics regime," Biophys. J. 61, 569-582 (1992).
    [CrossRef] [PubMed]
  8. X. Heng, X. Q. Cui, D. W. Knapp, J. G. Wu, Z. Yaqoob, E. J. McDowell, D. Psaltis, and C. H. Yang, "Characterization of light collection through a subwavelength aperture from a point source," Opt. Express 14, 10410-10425 (2006).
    [CrossRef] [PubMed]
  9. A. T. O'Neil and M. J. Padgett, "Rotational control within optical tweezers by use of a rotating aperture," Opt. Lett. 27, 743-745 (2002).
    [CrossRef]
  10. K. C. Neuman and S. M. Block, "Optical trapping," Review of Scientific Instruments 75, 2787-2809 (2004).
    [CrossRef]
  11. COMSOL_Multiphysics_3.3, in COMSOL Inc. (http://www.comsol.com/).

2006 (2)

X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, "Optofluidic microscopy- a method for implementing a high resolution optical microscope on a chip," Lab Chip 6,1274 - 1276 (2006).
[CrossRef] [PubMed]

X. Heng, X. Q. Cui, D. W. Knapp, J. G. Wu, Z. Yaqoob, E. J. McDowell, D. Psaltis, and C. H. Yang, "Characterization of light collection through a subwavelength aperture from a point source," Opt. Express 14, 10410-10425 (2006).
[CrossRef] [PubMed]

2004 (2)

K. C. Neuman and S. M. Block, "Optical trapping," Review of Scientific Instruments 75, 2787-2809 (2004).
[CrossRef]

J. Enger, M. Goksor, K. Ramser, P. Hagberg, and D. Hanstorp, "Optical tweezers applied to a microfluidic system," Lab Chip 4,196-200 (2004).
[CrossRef] [PubMed]

2002 (1)

2000 (1)

B. Hecht, B. Sick, U. P. Wild, V. Deckert, R. Zenobi, O. J. F. Martin, and D. W. Pohl, "Scanning near-field optical microscopy with aperture probes: Fundamentals and applications," J. Chem. Phys. 112, 7761-7774 (2000).
[CrossRef]

1992 (1)

A. Ashkin, "Forces of a single-beam gradient laser trap on a dielectric sphere in the ray optics regime," Biophys. J. 61, 569-582 (1992).
[CrossRef] [PubMed]

1986 (1)

Ashkin, A.

Baugh, L. R.

X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, "Optofluidic microscopy- a method for implementing a high resolution optical microscope on a chip," Lab Chip 6,1274 - 1276 (2006).
[CrossRef] [PubMed]

Bjorkholm, J. E.

Block, S. M.

K. C. Neuman and S. M. Block, "Optical trapping," Review of Scientific Instruments 75, 2787-2809 (2004).
[CrossRef]

Chu, S.

Cui, X. Q.

Deckert, V.

B. Hecht, B. Sick, U. P. Wild, V. Deckert, R. Zenobi, O. J. F. Martin, and D. W. Pohl, "Scanning near-field optical microscopy with aperture probes: Fundamentals and applications," J. Chem. Phys. 112, 7761-7774 (2000).
[CrossRef]

Dziedzic, J. M.

Enger, J.

J. Enger, M. Goksor, K. Ramser, P. Hagberg, and D. Hanstorp, "Optical tweezers applied to a microfluidic system," Lab Chip 4,196-200 (2004).
[CrossRef] [PubMed]

Erickson, D.

X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, "Optofluidic microscopy- a method for implementing a high resolution optical microscope on a chip," Lab Chip 6,1274 - 1276 (2006).
[CrossRef] [PubMed]

Goksor, M.

J. Enger, M. Goksor, K. Ramser, P. Hagberg, and D. Hanstorp, "Optical tweezers applied to a microfluidic system," Lab Chip 4,196-200 (2004).
[CrossRef] [PubMed]

Hagberg, P.

J. Enger, M. Goksor, K. Ramser, P. Hagberg, and D. Hanstorp, "Optical tweezers applied to a microfluidic system," Lab Chip 4,196-200 (2004).
[CrossRef] [PubMed]

Hanstorp, D.

J. Enger, M. Goksor, K. Ramser, P. Hagberg, and D. Hanstorp, "Optical tweezers applied to a microfluidic system," Lab Chip 4,196-200 (2004).
[CrossRef] [PubMed]

Hecht, B.

B. Hecht, B. Sick, U. P. Wild, V. Deckert, R. Zenobi, O. J. F. Martin, and D. W. Pohl, "Scanning near-field optical microscopy with aperture probes: Fundamentals and applications," J. Chem. Phys. 112, 7761-7774 (2000).
[CrossRef]

Heng, X.

X. Heng, X. Q. Cui, D. W. Knapp, J. G. Wu, Z. Yaqoob, E. J. McDowell, D. Psaltis, and C. H. Yang, "Characterization of light collection through a subwavelength aperture from a point source," Opt. Express 14, 10410-10425 (2006).
[CrossRef] [PubMed]

X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, "Optofluidic microscopy- a method for implementing a high resolution optical microscope on a chip," Lab Chip 6,1274 - 1276 (2006).
[CrossRef] [PubMed]

Knapp, D. W.

Martin, O. J. F.

B. Hecht, B. Sick, U. P. Wild, V. Deckert, R. Zenobi, O. J. F. Martin, and D. W. Pohl, "Scanning near-field optical microscopy with aperture probes: Fundamentals and applications," J. Chem. Phys. 112, 7761-7774 (2000).
[CrossRef]

McDowell, E. J.

Neuman, K. C.

K. C. Neuman and S. M. Block, "Optical trapping," Review of Scientific Instruments 75, 2787-2809 (2004).
[CrossRef]

O'Neil, A. T.

Padgett, M. J.

Pohl, D. W.

B. Hecht, B. Sick, U. P. Wild, V. Deckert, R. Zenobi, O. J. F. Martin, and D. W. Pohl, "Scanning near-field optical microscopy with aperture probes: Fundamentals and applications," J. Chem. Phys. 112, 7761-7774 (2000).
[CrossRef]

Psaltis, D.

X. Heng, X. Q. Cui, D. W. Knapp, J. G. Wu, Z. Yaqoob, E. J. McDowell, D. Psaltis, and C. H. Yang, "Characterization of light collection through a subwavelength aperture from a point source," Opt. Express 14, 10410-10425 (2006).
[CrossRef] [PubMed]

X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, "Optofluidic microscopy- a method for implementing a high resolution optical microscope on a chip," Lab Chip 6,1274 - 1276 (2006).
[CrossRef] [PubMed]

Ramser, K.

J. Enger, M. Goksor, K. Ramser, P. Hagberg, and D. Hanstorp, "Optical tweezers applied to a microfluidic system," Lab Chip 4,196-200 (2004).
[CrossRef] [PubMed]

Sick, B.

B. Hecht, B. Sick, U. P. Wild, V. Deckert, R. Zenobi, O. J. F. Martin, and D. W. Pohl, "Scanning near-field optical microscopy with aperture probes: Fundamentals and applications," J. Chem. Phys. 112, 7761-7774 (2000).
[CrossRef]

Sternberg, P. W.

X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, "Optofluidic microscopy- a method for implementing a high resolution optical microscope on a chip," Lab Chip 6,1274 - 1276 (2006).
[CrossRef] [PubMed]

Wild, U. P.

B. Hecht, B. Sick, U. P. Wild, V. Deckert, R. Zenobi, O. J. F. Martin, and D. W. Pohl, "Scanning near-field optical microscopy with aperture probes: Fundamentals and applications," J. Chem. Phys. 112, 7761-7774 (2000).
[CrossRef]

Wu, J. G.

Yang, C.

X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, "Optofluidic microscopy- a method for implementing a high resolution optical microscope on a chip," Lab Chip 6,1274 - 1276 (2006).
[CrossRef] [PubMed]

Yang, C. H.

Yaqoob, Z.

X. Heng, X. Q. Cui, D. W. Knapp, J. G. Wu, Z. Yaqoob, E. J. McDowell, D. Psaltis, and C. H. Yang, "Characterization of light collection through a subwavelength aperture from a point source," Opt. Express 14, 10410-10425 (2006).
[CrossRef] [PubMed]

X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, "Optofluidic microscopy- a method for implementing a high resolution optical microscope on a chip," Lab Chip 6,1274 - 1276 (2006).
[CrossRef] [PubMed]

Zenobi, R.

B. Hecht, B. Sick, U. P. Wild, V. Deckert, R. Zenobi, O. J. F. Martin, and D. W. Pohl, "Scanning near-field optical microscopy with aperture probes: Fundamentals and applications," J. Chem. Phys. 112, 7761-7774 (2000).
[CrossRef]

Biophys. J. (1)

A. Ashkin, "Forces of a single-beam gradient laser trap on a dielectric sphere in the ray optics regime," Biophys. J. 61, 569-582 (1992).
[CrossRef] [PubMed]

J. Chem. Phys. (1)

B. Hecht, B. Sick, U. P. Wild, V. Deckert, R. Zenobi, O. J. F. Martin, and D. W. Pohl, "Scanning near-field optical microscopy with aperture probes: Fundamentals and applications," J. Chem. Phys. 112, 7761-7774 (2000).
[CrossRef]

Lab Chip (2)

X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, "Optofluidic microscopy- a method for implementing a high resolution optical microscope on a chip," Lab Chip 6,1274 - 1276 (2006).
[CrossRef] [PubMed]

J. Enger, M. Goksor, K. Ramser, P. Hagberg, and D. Hanstorp, "Optical tweezers applied to a microfluidic system," Lab Chip 4,196-200 (2004).
[CrossRef] [PubMed]

Opt. Express (1)

Opt. Lett. (2)

Review of Scientific Instruments (1)

K. C. Neuman and S. M. Block, "Optical trapping," Review of Scientific Instruments 75, 2787-2809 (2004).
[CrossRef]

Other (3)

COMSOL_Multiphysics_3.3, in COMSOL Inc. (http://www.comsol.com/).

X. Q. Cui, X. Heng, W. W. Zhong, P. W. Sternberg, D. Psaltis, and C. H. Yang, "Imaging microorganisms with a high-resolution on-chip optofluidic microscope," submitted (2007).

D. Courjon, Near-field microscopy and near-field optics (London: Imperial College Press, 2003).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (5)

Fig. 1.
Fig. 1.

Illustration of the entire imaging system. Ti-Sapphire: Ti-Sapphire laser (λ=850 nm). f1: collimation lens (f1=3.5 cm). f2 (2 pieces): 4f scanning system (f2=10.0 cm). PZT: Piezo scanning tube (Physik Instrumente S-334). Cold mirror (R: 400–700 nm, T: 780 nm onward, from Newport). Objective lens: Olympus, 40X, NA=0.8, water, IR. Illumination source: white LED (Lamina, Titan series, daylight white). IR filter: Newport shortpass @ 650 nm. Recording CCD: Princeton Instruments (Spec10–100). Inset: zoom-in image of the Fig. 1 setup showing the 2D nanoaperture grid, its arrangement with the optical tweezer and the fluidic chamber.

Fig. 2.
Fig. 2.

(a). Image of the 2D nanoaperture grid shown on the recording CCD camera; there is no sample in this region. (b) The orientation of the nanoaperture grid with respect to the scanning direction of the sample. Lx : aperture spacing in x direction; Ly : spacing in y direction; θ: the angle between the scanning direction of the sample and the x-axis. (c) Scanning electron microscope (SEM) image of the nanoaperture grid. The substrate is aluminum. The inset shows one typical nanoaperture (D=100 nm).

Fig. 3.
Fig. 3.

Measurement of the resolution limit. (a) Illustration of the measurement scheme, where the NSOM probe was taken as a virtual point source. The tip was held in close proximity to the nanoaperture plane. (b) The point-spread-function profile of a typical nanoaperture as measured with the NSOM tip; the width was 170 nm (FWHM, red bar). The dark solid line was a Gaussian fit to the curve of the point spread function. * After accounting for the finite NSOM tip size, the near-field imaging resolution of this nanoaperture was established to be 110 nm (Sparrow’s criterion, green bar).

Fig. 4.
Fig. 4.

Strength of the asymmetric optical tweezer. (a) The deviation of the microsphere (diameter =10 µm) away from its origin in the lateral plane. (b) The deviation of the microsphere (diameter =1 µm) away from its origin.

Fig. 5.
Fig. 5.

(a). Example of the transmission time-of-flight traces from two nanoapertures that are in the same row but 25 µm apart; these two apertures scan different segments (0.75 µm apart in y direction) of the sample: a pollen spore. (b, c) Microscope images of two paper mulberry pollen spores. The microscope setup was the same as Fig. 1 except that the nanoaperture plate was removed. (d) Microscope image of a 10µm polystyrene microsphere. (e, f) OFM images of two paper mulberry pollen spores. (g) OFM image of a 10µm microsphere.

Equations (4)

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

Δ t = L x cos θ V
Δ t = L x cos θ V ( n 1 ) L y sin θ V ( m 1 )
δ y = L x sin ( θ )
δ x = V δ t

Metrics