Research
In traditional imaging approaches an optical system generates a 2D image of an object on a photographic film or a pixelated sensor such as a CCD. The point spread function (PSF) of the optical system is engineered to be as small as possible to provide a sharp image. An aberrated optical system has a complex, wide PSF, which in traditional imaging reduces resolution. In computational imaging, we use the fact that the PSF of an aberrated system contains extra information that is not otherwise available, such as the depth (distance between object and camera). As an outlook, the PSF could also be used for hyperspectral imaging.

Several computational imaging approaches have been developed especially based on compressive sensing. In the most dramatic cases strong aberrations are introduced on purpose to make the PSF more complex. The resulting aberrated image is recorded with a megapixel sensor, which allows the extraction of a high-resolution sharp image as well as the desired depth information. This approach of replacing glass by silicon, i.e., reducing optical complexity by adding computation and a surplus of sensor pixels, is especially valuable in industrial, mobile or handheld applications where cost, mass, robustness and lack of moving parts are important factors.

In collaboration with our industrial partner DEMCON-Focal, we will develop a computational imaging approach that can measure 3D surface profiles, such as the face of an antique coin or verify the shape of a 3D-printed object with few-micrometer resolution in a single shot, using the property of aberrated optics to code depth information into the PSF. The optics will provide input to reconstruction algorithms extract both the corrected image and the PSF. An extension of this principle to hyperspectral imaging may be considered. The present research project is part of the “TTW-Perspectief” program “Synoptics” in which several Dutch Universities collaborate with industrial partners to develop innovative optical technologies.

This position is part of the Synoptics programme and will benefit from the interactions with academic partners at TU Delft, Leiden, Twente and Nijmegen, and with industrial partners. Read more here.  

About the position
As a PhD student you will be a junior member of the Nanophotonics research group. You will be encouraged to pursue your research goals with guidance from senior members of the group, and reach a level of independence commensurate with the PhD degree in 4 years. Open collaboration, diversity, the highest level of research integrity and a safe and pleasant working environment are core values of the group. Part of the developments of instruments and software will take place at DEMCON-Focal, and you will regularly work together with employees there on designs and algorithms. Some of your work at DEMCON-Focal will be covered by confidentiality agreements, which will be formulated to balance confidentiality with sufficient freedom to publish according to the rules of the NWO-TTW Perspectief program.

You will report on your results at national and international meetings, through peer-reviewed publications, and in the form of a PhD thesis. You will benefit from the expertise of the Nanophotonics group of the Debye Institute for Nanomaterials Science. As a member of this world-leading interdisciplinary institute you will have access to a wide range of laboratory infrastructure, instrumentation, and technical support. Furthermore, the Complexity Center at the UU offers courses and expertise in data science and applications related to machine learning.

We are looking for a creative and open-minded physicist with a strong interest in physical optics and data analysis algorithms. Experience with programming and data acquisition is considered advantageous. Scientific curiosity, skill in design and integration of experiments and integration of analytic capabilities with a decisive approach will bring you toward success in this project. In addition, because you will be part of a consortium, good communication skills and a genuine interest in different branches of science and engineering are very important.

• a full-time PhD position, initially for one year with extension to four years in total upon a successful assessment in the first year, and with the specific intent that it results in a doctorate within this period;
• a full-time gross salary that starts at €2,395 and increases to €3,061 per month in the fourth year (scale P of the Collective Labour Agreement Dutch Universities (cao));
• benefits including 8% holiday bonus and 8.3% end-of-year bonus;
• a pension scheme, partially paid parental leave, and flexible employment conditions based on the Collective Labour Agreement Dutch Universities.

In addition to the employment conditions laid down in the CAO for Dutch Universities, Utrecht University has a number of its own arrangements. For example, there are agreements on professional development, leave arrangements and sports. We also give you the opportunity to expand your terms of employment yourself via the Employment Conditions Selection Model. This is how we like to encourage you to continue to grow.

More information about working at the Faculty of Science can be found here.

The Nanophotonics group performs innovative experiments on light-matter interaction in complex photonic matter. Our work connects to applications in sustainable technology, semiconductor manufacturing, photonic computing and biomedical research. Laser systems that achieve or exceed the state of the art in stability, pulse energy or controllability enable us to produce world-leading results in the study of ultracold gases, strongly scattering media, nonlinear photonics and photonic quantum fluids. A wide network of academic and industrial collaborations provides context for our research and opportunities for our group members and students.

At the Faculty of Science there are 6 departments to make a fundamental connection with: Biology, Chemistry, Information and Computing Sciences, Mathematics, Pharmaceutical Sciences and Physics. Within each department there are distinct institutes which focus on answering some of humanity’s most pressing problems. These institutes are further broken up into research groups.

Utrecht University is a friendly and ambitious university at the heart of an ancient city. We love to welcome new scientists to our city – a thriving cultural hub that is consistently rated as one of the world’s happiest cities. We are renowned for our innovative interdisciplinary research and our emphasis on inspirational research and excellent education. We are equally well-known for our familiar atmosphere and the can-do mentality of our people. This lively and inspiring academic environment attracts professors, researchers and PhD candidates from all over the globe, making both the University and the Faculty of Science a vibrant international and wonderfully diverse community.