In-line color digital holographic microscope for water quality measurements

Gӧrӧcs, Zoltán; Orzó, Lászlò; Kiss, Margit; Tóth, Veronika; Tőkés, Szabolcs

doi:10.1117/12.871098

Cited by 19 publications

(16 citation statements)

References 17 publications

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“…Our DHM setup records high resolution Gabor-type [1,21] in-line holograms, as it utilize the space bandwidth product more efficiently than the other architectures [20]. Using a single recorded hologram we are able to inspect orders of magnitude larger volume compared to approaches that applies conventional microscopy [5] where the depth of focus is constrained considerably by the requested lateral resolution.…”

Section: Introductionmentioning

confidence: 88%

“…To provide proper illumination in our color DHM, previously we coupled the light of the applied three different fiber coupled lasers into the same optical fiber using special fiber couplers [19,20]. Although this type of coupling is simple and straightforward, it has severe shortcomings: First of all, the couplings are usually accompanied by considerable light losses.…”

Section: Coherent Multicolor Illumination Implementation In the Dhmmentioning

confidence: 99%

“…It is able to determine microbiological content (algae and worms) of the natural and drinking water samples automatically. These data can be efficiently used to monitor the microorganisms in natural water bodies, and to characterize the quality of the filtration process in water wells [19,20].…”

Section: Introductionmentioning

confidence: 99%

“…Using the holographic volumetric imaging technique we have developed a DHM [19,20] for biological water quality monitoring purposes. It is able to determine microbiological content (algae and worms) of the natural and drinking water samples automatically.…”

Section: Introductionmentioning

confidence: 99%

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Special multicolor illumination and numerical tilt correction in volumetric digital holographic microscopy

Kiss¹,

Nagy²,

Lakatos³

et al. 2014

Opt. Express

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Abstract:We introduce a color imaging method in our digital holographic microscope system (DHM). This DHM can create color images of freely floating, or moving objects inside a large volume by simultaneously capturing three holograms using three different illumination wavelengths. In this DHM a new light source assembly is applied, where we use single mode fibers according to the corresponding wavelengths that are tightly and randomly arranged into a small array in a single FC/PC connector. This design has significant advantages over the earlier approaches, where all the used illuminations are coupled in the same fiber. It avoids the coupling losses and provides a cost effective, compact solution for multicolor coherent illumination. We explain how to determine and correct the different fiber end positions caused tilt aberration during the hologram reconstruction process. To demonstrate the performance of the device, color hologram reconstructions are presented that can achieve at least 1 µm lateral resolution.

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Section: Introductionmentioning

confidence: 88%

Section: Coherent Multicolor Illumination Implementation In the Dhmmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Special multicolor illumination and numerical tilt correction in volumetric digital holographic microscopy

Kiss¹,

Nagy²,

Lakatos³

et al. 2014

Opt. Express

Self Cite

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show abstract

“…This step, called "mosaicking", is mandatory to record color images with this type of sensor, since the photodetectors used are sensitive to incident wave intensity over a wide spectral range. Spectral crosstalk is due to the Bayer filter covering the photodetector layer of the CMOS color sensors: their spectral responses are not ideal bandpass [25]. Figure 3 shows the spectral responses as a function of the wavelength for the filters of the Basler™ daA2500-14uc camera.…”

Section: Spectral Crosstalkmentioning

confidence: 99%

Self-calibration for lensless color microscopy

et al. 2017

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Lensless color microscopy (also called in-line digital color holography) is a recent quantitative 3D imaging method used in several areas including biomedical imaging and microfluidics. By targetting cost effective and compact designs, the wavelength of the low-end sources used is only imprecisely known, in particular because of their temperature and power supply voltage dependence. This imprecision is the source of biases during the reconstruction step. An additional source of error is the crosstalk phenomenon, i.e., the mixture in color sensors of signals originating from different color channels. We propose to use a parametric inverse problem approach to achieve the self-calibration of a digital color holographic setup. This process provides an estimation of the central wavelengths and of the crosstalk. We show that taking the crosstalk phenomenon into account in the reconstruction step improves its accuracy.

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