The department of Imaging Physics develops novel instrumentation and imaging technologies. We are driven by our scientific curiosity and problem oriented nature in research with a strong connection to industry and to educate future leaders in the field of imaging science.
The scientific staff of the department is formed by independent Principle Investigators or Educators.
14 October 2016
OP: Thomas van den Hooven started his BSc project
Thomas has started his BSc project which focusses on the modelling a computational hyperspectral imaging device. His supervisors are Paul Urbach, Yifeng Shao and Matthias Strauch. Most hyperspectral imaging devices ‘scan’ their object in wavelength: a picture is taken for every wavelength and later this data is merged. This device will rather scan the hyperspectral electromagnetic field emitted by the object using a spatial light modulator (SLM): one moving point will scan along the SLM and another point will be used as a reference. The light transmitted through the SLM will then interfere, making it possible to obtain relative phase and amplitude information for each wavelength at each point of the SLM. The advantages of this method are evident, using a fast SLM, the needed interference patterns can be captured relatively quick. Also, the method can in theory process a lot of wavelength at once. Unfortunately, the method also requires a lot of processing power. The goal of this project is to find of this method is feasible to be used as an alternative in hyperspectral imaging.
13 October 2016
OP: Ruben Biesheuvel started his MSc project
Ruben has started his MSc project which focusses on testing different algorithms of retrieving the Zernike Polynomial coefficients that describes a certain wavefront. This is a joint project between the Optics group and the CSI2 group of the DCSC (3mE), with Silvania Pereira and Paolo Pozzi as supervisors. A Shack-Hartmann sensor is widely used to measure the wavefront, but rather than directly measuring it, the Shack-Hartmann sensor is only able to measure the derivatives. For this reason, reconstruction can be troublesome for a quickly varying wavefront. Janssen has found an analytical relation between the slope of the wavefront and Zernike Coefficients to describe the wavefront. The hypothesis is that this method could be more accurate for quickly varying wavefronts. In order to test the accuracy, an adaptive optics setup is built. In the beginning of the project, a deformable membrane mirror will be used in order to introduce specific aberrations in the wavefront, and these aberrations will be measured using the Shack-Hartmann sensor and independently with an interferometer. The algorithms that will be tested are a well-known Least Squares method, an iterative integration method and Janssen’s method. If successful, a spatial light modulator will be used in order to create more extreme cases of quickly varying wavefronts.  Janssen, A. J. E. M. "Zernike expansion of derivatives and Laplacians of the Zernike circle polynomials." JOSA A 31.7 (2014): 1604-1613.
17 February 2022
Freek Pols: "How can we effectively teach students how to engage in scientific inquiry?"
What does this entail and how can we assess whether students acquired the associated knowledge? These are questions addressed in our paper "Defining and assessing understandings of evidence with the assessment rubric for physics inquiry: Towards integration of argumentation and inquiry". The premise of this study is that an inquiry comes down to the building of a scientifically cogent argument where each decision and action undertaken is substantiated.
16 February 2022
Cristina Creţu joined ImPhys as MSc student
Cristina is a Biomedical Engineering Master student in the Medical Physics track. She is working on the Fourier decomposition MRI for pediatric lung diseases under supervision of Frans Vos.
From light spots to supersharp images
Making detailed 3D images of proteins in living cells with a special light microscope, without damaging those cells. That is what Sjoerd Stallinga, winner of an ERC Advanced grant worth 2.3 million euros, wants to achieve. In order to do so he is going to scan samples nanometer by nanometer using a sophisticated 3D light pattern in an approach that requires extensive collaboration between different disciplines.
Spotlight on aggressive cancer cells
Metastases in cancer are often caused by a few abnormal cells. These behave more aggressively than the other cancer cells in a tumour. Miao-Ping Chien and Daan Brinks are working together, from two different universities, on a method to detect these cells. Their research has now been published in Nature Biomedical Engineering
How to find structurally different molecules before they disappear in the average?
Particle fusion for single molecule localization microscopy improves signal-to-noise ratio and overcomes underlabeling, but ignores structural heterogeneity or conformational variability. This study presents a-priori knowledge-free unsupervised classification of structurally different particles employing the Bhattacharya cost function as dissimilarity metric.
The impact of noise on Structured Illumination Microscopy image reconstructions
Super-resolution structured illumination microscopy (SIM) has become a widely used method for biological imaging. Standard reconstruction algorithms, however, are prone to generate noise-specific artifacts that limit their applicability for lower signal-to-noise data. Here we present a physically realistic noise model that explains the structured noise artifact, which we then use to motivate new complementary reconstruction approaches.
A new tool to understand the brain
How does our brain work? An international team of researchers, including lead author Daan Brinks of TU Delft, has taken another step towards answering that question. They have created a new tool that allows them to image electrical signals in brains with an unprecedented combination of precision, resolution, sensitivity, and depth.
Researchers make 3D image with light microscope
For the first time, Delft researchers have succeeded in making a three-dimensional image of a cellular component using light. The component in question is the nuclear pore complex: tunnels that facilitate traffic to and from the cell nucleus. Studying cell components in 3D can help to determine the cause of various diseases, among other things. The researchers have published their findings in Nature Communications.
Decoding movement intentions in the brain using ultrasound waves
While many techniques can image brain activity, this was the first time that a new technology, called functional ultrasound imaging, was used to detect motor planning deep within the brain. The team is now applying functional ultrasound decoding to more complicated motor control tasks. At ImPhys, Dr. Maresca is developing ultrasound technologies to image brain activity down to the cellular scale.