Merry Christmas and a Happy New Year

Holographic tomography is a technique, which delivers quantitative information on the refractive index of a sample based on multiple holographic projections. The method is marker-free and suitable to live cell imaging and thus gains attention in the area of biomedical imaging.¹ However, it can also be used to measure technical object such as calibration phantoms manufactured with direct laser writing.² In this paper we prepared a step object (50x50x20 µm), which was based on a cartoon of a Santa Claus and measured its 3D refractive index distribution with holographic tomography. 

Figure 1. Manufacturing and measurement process of a Santa Claus phase map:
a) Santa Claus cartoon³ - RGB source image,
b) source image converted to grayscale values, which encode step height,
c) step map for printing,
d) post-print preview,
e) hologram of a Santa,
f) maximum intensity projection of the 3D refractive index distribution.

References:
[1] Popescu, G. and Park, Y., “Quantitative phase imaging in biomedicine,” Nature Photonics 12, 578–589 (2018).
[2] Ziemczonok, M., Kuś, A., Wasylczyk, P., and Kujawińska, M., “3D-printed biological cell phantom for testing 3D quantitative phase imaging systems,” Scientific Reports 9, 1–9 (2019).
[3] Shutterstock, “Shutterstock santa claus holding a gift box,” (2021).

May the spirit of Christmas bring you and your family hope, happiness and love - Merry Christmas and Happy New Year 2022

Arkadiusz Kuś, Emilia Wdowiak, Michał Ziemczonok, Wojciech Krauze, Maria Baczewska, Piotr Stępień and Małgorzata Kujawińska