Partially coherent light-emitting diode illumination for video-rate in-line holographic microscopy.

The light of a light-emitting diode or a common thermal source, such as a tungsten filament lamp, is known to be quasi-incoherent. We generated partially coherent light of these sources with a volume of coherence in the micrometer range of 5-100 μm3 by spatial and spectral filtering. The corresponding degree of partial coherence was adapted for microscopic interference setups, such as a digital in-line holographic microscope. The practicability of the sources was determined by the spectral emittance and the resulting signal-to-noise ratio (SNR) of the detector. The microscale coherence in correlation with the SNR and its resolution for microscopy were analyzed. We demonstrate how low-light-level, non-laser sources enable holographic imaging with a video frame rate (25 frames/s), an intermediate SNR of 8 dB, and a volume of coherence of 3.4×10(4) μm3. Holograms of objects with a lateral resolution of 1 μm were achieved using a microscope lens (50×/NA=0.7) and a CCD camera featuring a 4-12 bit dynamic range.

[1]  Manfred H. Jericho,et al.  4-D imaging of fluid flow with digital in-line holographic microscopy , 2008 .

[2]  Ichirou Yamaguchi,et al.  Effects of quantization in phase-shifting digital holography. , 2005, Applied optics.

[3]  R. Riesenberg,et al.  Spatial coherence on micrometer scale measured by a nanohole array , 2012 .

[4]  Nitesh Pandey,et al.  Quantization noise and its reduction in lensless Fourier digital holography. , 2011, Applied optics.

[5]  Etienne Cuche,et al.  Shot-noise influence on the reconstructed phase image signal-to-noise ratio in digital holographic microscopy. , 2006, Applied optics.

[6]  A. Ozcan,et al.  Lensfree on-chip microscopy over a wide field-of-view using pixel super-resolution , 2010, Optics express.

[7]  D. Brady,et al.  Video-rate compressive holographic microscopic tomography. , 2011, Optics express.

[8]  A. Rosenhahn,et al.  Flow conditions in the vicinity of microstructured interfaces studied by holography and implications for the assembly of artificial actin networks. , 2011, Physical chemistry chemical physics : PCCP.

[9]  F. Zernike.  The concept of degree of coherence and its application to optical problems , 1938 .

[10]  Arthur A. Webster,et al.  Resolution limits for coherent optical imaging: signal-to-noise analysis in the spatial-frequency domain , 1992 .

[11]  Anne Margarette S Maallo,et al.  Quantization analysis of speckle intensity measurements for phase retrieval. , 2010, Applied optics.

[12]  D. Gabor.  A New Microscopic Principle , 1948, Nature.

[13]  Frank Dubois,et al.  Partial spatial coherence effects in digital holographic microscopy with a laser source. , 2004, Applied optics.

[14]  R Riesenberg,et al.  Reconstruction of high-resolution holographic microscopic images. , 2009, Optics letters.

[15]  F. Dubois,et al.  Improved three-dimensional imaging with a digital holography microscope with a source of partial spatial coherence. , 1999, Applied optics.

[16]  Rainer Riesenberg,et al.  Empfindliches Messen partieller Kohärenz mit Pinhole-Array , 2010 .

[17]  Derek Tseng,et al.  Lensfree microscopy on a cellphone. , 2010, Lab on a chip.

[18]  J. Olivo-Marin,et al.  Off-axis compressed holographic microscopy in low-light conditions. , 2011, Optics letters.

[19]  Richard Kowarschik,et al.  Optimized coherence parameters for high-resolution holographic microscopy , 2012 .

[20]  Stefan Sinzinger,et al.  Information extraction from digital holograms for particle flow analysis , 2010 .

[21]  Peter Klages,et al.  Digital in-line holographic microscopy. , 2006 .

[22]  P. H. Cittert,et al.  Die Wahrscheinliche Schwingungsverteilung in Einer von Einer Lichtquelle Direkt Oder Mittels Einer Linse Beleuchteten Ebene , 1934 .

[23]  A. Khintchine.  Korrelationstheorie der stationären stochastischen Prozesse , 1934 .

[24]  L. Repetto,et al.  Lensless digital holographic microscope with light-emitting diode illumination. , 2004, Optics letters.

[25]  Manfred H. Jericho,et al.  In-line digital holographic microscopy for terrestrial and exobiological research , 2010 .

[26]  M. Atlan,et al.  Digital holography with ultimate sensitivity. , 2008, Optics letters.

[27]  G. Pedrini,et al.  Short coherence digital holography for 3D microscopy , 2001 .

[28]  N. Wiener.  Generalized harmonic analysis , 1930 .

[29]  Wolfgang Osten,et al.  Coherence effects in digital in-line holographic microscopy. , 2008, Journal of the Optical Society of America. A, Optics, image science, and vision.

[30]  Patrik Langehanenberg,et al.  Characterisation of light emitting diodes (LEDs) for application in digital holographic microscopy for inspection of micro and nanostructured surfaces , 2008 .