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.
31 October 2016
OP: Erik Swarts started his BSc project
Erik started his BSc project on analytical solution for dipoles in multilayer systems". His supervisors are Aurele Adam & Johan Dubbeldam. The goal of the project project is to find a general analytical solution for the electromagnetic field inside dipole-doped one-dimensional optical multilayer systems, and also to calculate reflection and transmission coefficients of incoming electromagnetic waves. The resulting algorithm should provide a solution for a system having arbitrarily many layers and dipoles inside them. A numerical matrix solution for this problem already exists, but an analytical solution can provide overall stability and significantly faster calculations. The research is based on an existing technique, that uses extended Fabry-Perot equations to calculate transmission and reflection in regular (no dipole containing) multilayer systems, that will be extended to calculate what we need. Once this solution is retrieved, the next goal is to optimise this alghoritm for even faster calculation. The results of this project could probably be used to enhance the performance of optical multilayer coatings or small light emitting devices. Since the computational properties of the algorithm will be better, these improvements can be done more efficiently.
27 October 2016
AWI: Farewell Aramco Overseas
Since 2012 Saudi Aramco has located one of their Global Research Centers inside our university. To extend their activities, they have chosen for a new office location at Delftechpark. As this is still close to our university, the intensive research cooperation in the field of oil and gas exploration and monitoring will remain unchanged. The main task of the Aramco Research Center in Delft is to improve seismic data processing to get a sharper image of the subsurface, which allows it to obtain more reliable information upon which drilling decisions can be based. With backgrounds in math, physics and software development they have strong relationships with our acoustical imaging research group (AWI), as we develop cutting-edge technology for the oil and gas industry within the framework of the Delphi consortium, for which Saudi Aramco is one of the sponsors. We would like to congratulate Saudi Aramco with their new office and are looking forward to a fruitful continuation of our cooperation.
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.
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.