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thus the field of view to a few 100 lm. We record a lateral resolution of 0.78 lm in transmission mode and 0.98 lm in reflection mode. The difference in resolution between transmission and reflection is likely due to aberrations of the reference wave, which is assumed to be spherical. In reflection mode, the reference wave is submitted to greater degradations than in transmission mode. Especially for the measurement of the resolution target, the reference wave is generated by an additional lens in front of the beam splitter, which is reflected by a reference mirror behind the beam splitter. Consequently, the reference wave is degraded by spherical aberrations due to the double transmission through the beam splitter as well as degradations from imperfections of the lens and its alignment.
The reconstruction process assumes a perfectly spherical reference wave. To achieve diffraction limited resolution in both transmission and reflection modes across larger fields of view, additional calibration of the reference wave is needed. For this, we will implement an additional wavefront measurement using, e. g., a Shack – Hartmann sensor or computational shear-interferometry [ 36 ] in future research. The measured wavefront errors, differing from an ideal spherical wave, can be digitally compensated. Initial simulations show that compensating wavefront errors would allow for sub-micron resolution across several mm to cm diameter fields of view.
An alternative way to reduce degradations of the reference wave is to use a lensless holographic Gabor configuration for measurements in transmission mode. Using a single light source the non-diffracted light acts as a reference wave. This would especially eliminate degradations stemming from beam splitters. Future investigations will include transmission measurements in Gabor configuration.
Acknowledgments
The authors thank Manfred Radmacher( Universität Bremen) for sharing PANC1 cells and Sander van der Driesche( Universität Bremen) for preparing the PANC1 cells for measurement, as well as Reiner Klattenhoff and Bennet Wucherpfennig for their support with the experimental measurements.
Funding
The authors gratefully acknowledge the support of the Deutsche Forschungsgemeinschaft( DFG, German Research Foundation) for funding this work under the project“ HyperCOMet”, grant no. 430572965.
Conflicts of interest The authors declare no conflicts of interest.
Data availability statement
The Data underlying the presented results and the used Matlab algorithms may be obtained from the authors upon a reasonable request.
Author contribution statement
Conceptualization, C. F.; Data curation, A. F. M. and C. F.; Investigation, A. F. M., J. A. B.; Methodology, A. F. M. and C. F.; Validation, A. F. M., J. A. B. and C. F.; Visualization, A. F. M., J. A. B. and
C. F..; Formal Analysis, A. F. M. and C. F.; Writing – original draft, A. F. M., and C. F.; Funding acquisition, R. B. B.; Supervision and discussion of results, R. B. B. and C. F. All authors have read and agreed to the submitted version of the manuscript.
References
1 Schnars U, Falldorf C, Watson J, Jüptner W, Digital holography and wavefront sensing( Springer, 2015). 2 Falldorf C, Thiemicke F, Müller AF, Agour M, Bergmann RB, Flash-profilometry fullfield lensless acquisition of spectral holograms for coherence scanning profilometry, Opt. Expr. 31( 17), 27494 – 27507( 2023).
3 de Groot PJ, Deck LL, Su R, Osten W,, Contributions of holography to the advancement of interferometric measurements of surface topography, Light: Adv. Manuf. 3( 1), 1 – 20( 2022).
4 Fratz M, Seyler T, Bertz A, Carl D, Digital holography in production: an overview, Light: Adv. Manuf. 2( 3), 283 – 295( 2021).
5 Balasubramani V, Kuś A, Tu HY, Cheng CJ, Baczewska M, Krauze W, et al., Holographic tomography: techniques and biomedical applications, Appl. Opt. 60( 10), B65 – B80( 2021).
6 An J, Won K, Kim Y, Hong JY, Kim H, Kim Y, et al., Slimpanel holographic video display, Nat. Commun. 11( 1), 5568( 2020).
7 Falldorf C, Rukin I, Müller AF, Kroker S, Bergmann RB, Functional pixels: a pathway towards true holographic displays using today’ s display technology, Opt. Expr. 30( 26), 47528 – 47540( 2022). 8 Ozcan A, McLeod E, Lensless imaging and sensing, Annu.
Rev. Biomed. Eng. 18, 77 – 102( 2016). 9 Kim J, Lee SJ, Digital in-line holographic microscopy for label-free identification and tracking of biological cells, Mil. Med. Res. 11( 1), 38( 2024).
10 Boominathan V, Robinson JT, Waller L, Veeraraghavan A, Recent advances in lensless imaging, Optica. 9( 1), 1 – 16( 2022).
11 Falldorf C, Müller AF, Pazos BGC, Bich JA, Bergmann RB, Current progress in lensless holographic microscopy, in 3D Imag Visual Disp., Vol. 13465( SPIE, 2025), pp. 19 – 26.
12 Tobon-Maya H, Zapata-Valencia S, Zora-Guzmán E, Buitrago-Duque C, Garcia-Sucerquia J, Open-source, costeffective, portable, 3D-printed digital lensless holographic microscope, Appl. Opt. 60( 4), A205 – A214( 2021).
13 Chen D, Wang L, Luo X, Xie H, Chen X, Resolution and contrast enhancement for Lensless digital holographic microscopy and its application in biomedicine, Photonics 9( 5), 358( 2022).
14 Gao P, Yuan C, Resolution enhancement of digital holographic microscopy via synthetic aperture: a review, Light: Adv. Manuf. 3( 1), 105 – 120( 2022).
15 Massig JH, Digital off-axis holography with a synthetic aperture, Opt. Lett. 27( 24), 2179 – 2181( 2002).
16 Greenbaum A, Zhang Y, Feizi A, Chung PL, Luo W, Kandukuri SR, et al., Wide-field computational imaging of pathology slides using lens-free on-chip microscopy, Sci. Transl. Med. 6( 267), 267ra175 – 5( 2014).
17 Bianco V, Paturzo M, Ferraro P, Spatio-temporal scanning modality for synthesizing interferograms and digital holograms, Opt. Expr. 22( 19), 22328 – 22339( 2014).
18 Su TW, Isikman SO, Bishara W, Tseng D, Erlinger A, Ozcan A, Multi-angle lensless digital holography for depth resolved imaging on a chip, Opt. Expr. 18( 9), 9690 – 9711( 2010).