Abstract

We demonstrate an optical method for edge contrast enhancement in light microscopy. The method is based on holographic Fourier plane filtering of the microscopic image with a spiral phase element (also called vortex phase or helical phase filter) displayed as an off-axis hologram at a computer controlled high resolution spatial light modulator (SLM) in the optical imaging pathway. The phase hologram imprints a helical phase term of the form exp() on the diffracted light field in its Fourier plane. In the image plane, this results in a strong and isotropic edge contrast enhancement for both amplitude and phase objects.

© 2005 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |

  1. N. R. Heckenberg, R. McDuff, C. P. Smith, and A. G. White, �??Generation of optical phase singularities by computer-generated holograms,�?? Opt. Lett. 17, 221�??223 (1992)
    [CrossRef] [PubMed]
  2. R. Oron, N. Davidson, A. A. Friesem, and E. Hasman, �??Transverse mode shaping and selection in laser resonators,�?? Progress in Optics 42, 325�??386 (2001)
    [CrossRef]
  3. S. S. R. Oemrawsingh, J. A.W. van Houwelingen, E. R. Eliel, J. P.Woerdman, E. J. K. Verstegen, J. G. Kloosterboer, and G. W. �??t Hooft, �??Production and characterization of spiral phase plates for optical wavelengths,�?? Appl. Opt. 43, 688�??694 (2004)
    [CrossRef] [PubMed]
  4. A. Y. M. NG, C. W. See, and M. G. Somekh, �??Quantitative optical microscope with enhanced resolution using a pixelated liquid crystal spatial light modulator,�?? J. Microscopy 214, 334�??340 (2004)
    [CrossRef]
  5. J. A. Davis, D. E. McNamara, D. M. Cottrell, and J. Campos, �??Image processing with the radial Hilbert transform: theory and experiments,�?? Opt. Lett. 25, 99�??101 (2000)
    [CrossRef]
  6. K. Crabtree, J. A. Davis, and I. Moreno, �??Optical processing with vortex-producing lenses,�?? Appl. Opt. 43, 1360�??1367 (2004)
    [CrossRef] [PubMed]
  7. G. A. Swartzlander, Jr., �??Peering into darkness with a vortex spatial filter,�?? Opt. Lett. 26, 497�??499 (2001)
    [CrossRef]
  8. M. R. Arnison, K. G. Larkin, C. J. R. Sheppard, N. I. Smith, and C. J. Cogswell, �??Linear phase imaging using differential interference contrast microscopy,�?? J. Microscopy 214, 7�??12 (2004)
    [CrossRef]
  9. G. O. Reynolds, J. B. DeVelis, G. B. Parrent, Jr., and B. J. Thompson, The new physical optics notebook: Tutorials in Fourier optics (SPIE Optical Engineering Press, Bellingham, Washington, 1989)
    [CrossRef]
  10. K. G. Larkin, D. J. Bone, and M. A. Oldfield, �??Natural demodulation of two-dimensional fringe patterns. I. General background of the spiral phase quadrature transform,�?? J. Opt. Soc. Am. A, 18, 1862�??1870 (2001)
    [CrossRef]
  11. A. Jesacher, S. F¨urhapter, S. Bernet, and M. Ritsch-Marte , �??Diffractive optical tweezers in the Fresnel regime,�?? Opt. Express 12, 2243-2250 (2004), //www.opticsexpress.org/abstract.cfm?URI=OPEX-12-10-2243
    [CrossRef] [PubMed]

Appl. Opt. (2)

J. Microscopy (2)

M. R. Arnison, K. G. Larkin, C. J. R. Sheppard, N. I. Smith, and C. J. Cogswell, �??Linear phase imaging using differential interference contrast microscopy,�?? J. Microscopy 214, 7�??12 (2004)
[CrossRef]

A. Y. M. NG, C. W. See, and M. G. Somekh, �??Quantitative optical microscope with enhanced resolution using a pixelated liquid crystal spatial light modulator,�?? J. Microscopy 214, 334�??340 (2004)
[CrossRef]

J. Opt. Soc. Am. A (1)

Opt. Express (1)

Opt. Lett. (3)

Progress in Optics (1)

R. Oron, N. Davidson, A. A. Friesem, and E. Hasman, �??Transverse mode shaping and selection in laser resonators,�?? Progress in Optics 42, 325�??386 (2001)
[CrossRef]

Other (1)

G. O. Reynolds, J. B. DeVelis, G. B. Parrent, Jr., and B. J. Thompson, The new physical optics notebook: Tutorials in Fourier optics (SPIE Optical Engineering Press, Bellingham, Washington, 1989)
[CrossRef]

Supplementary Material (1)

» Media 1: MPG (1037 KB)     

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 (4)

Fig. 1.
Fig. 1.

Simulation of the imaging of a circular phase step for the phase contrast and for the spiral phase contrast method. Image A shows the result for phase contrast imaging of a phase step of 0.25% of the optical wavelength. The image contrast is 6%. In B the same simulation is performed for spiral phase imaging. There the image contrast is 100%. The graph at the right shows the resulting image contrast of the phase contrast method (oscillating) and the spiral phase contrast method (equals 1 at any point).

Fig. 2.
Fig. 2.

Sketch of our experimental setup. The displayed holograms A-D used for certain spatial filtering purposes in the Fourier plane are not to scale. Details of the experiment are explained in the text.

Fig. 3.
Fig. 3.

From the left: Bright-field, spiral phase contrast and dark-field image of an absorptive sample (resolution target, size of the total image area is 400×300 microns), imaged in transmission geometry. The three images were taken under identical illumination and camera settings.

Fig. 4.
Fig. 4.

(1.04 MBytes) Contrast enhancement of phase objects. Two pairs (A–B, and C–D) of bright-field images (A, C) and spiral phase filtered images (B, D) of the same sample areas of a phase object. In A–B the sample consisted of a scratch in a glass coverslip, coated with water. The attached movie shows an extended scan over a larger sample area, comparing the two imaging modes. In (C) and (D) another sample is imaged, consisting of a sharp oil-water boundary.

Metrics