Harald Homulle

PhD student at the Applied Quantum Architectures Group of the Faculty of Engineering, Mathematics and Computer Science (EEMCS/EWI), Delft University of Technology.


The main project I am currently working on is designing and testing of electronics working at cryogenic temperatures. The main focus is to have electronics working at 4K (-269°C) as the main control interface for quantum computers. Partly, the electronics needs to go together with the qubits in mK temperatures.

My main focus is cryogenic FPGAs and other commercial electronics at cryogenic temperatures. Besides that there is a lot of involvement in transistor testing and designing of integrated circuits optimized for low temperatures.


Commercial FPGAs are working at temperatures as low as 4K. This piece of hardware is very useful in any quantum control loop, but potentially in many more applications were the use of cold electronics is desired, such as astronomy and space applications.

For the FPGA various firmwares were development, one example is our time-to-digital converter, which basic version is available online here. Even more interesting is the design of a 1 GSa/s ADC, operating completely inside the FPGA while using TDCs for the actual conversion. 

Transistors were tested at various temperatures down to 4K of various process technologies, such as 160 and 40 nm transistors.

Also I designed various dip-sticks to cool our electronics down to 4K, a small movie is available in the movies section below.

Besides cryogenic electronics, I have been working on biomedical imaging; mainly fluorescence lifetime imaging.




  1. M. Turchetti, H. Homulle, F. Sebastiano, G. Ferrari, E. Charbon and E. Prati, Tunable single hole regime of a silicon field effect transistor in standard CMOS technology,
    Applied Physics Express (9), pp. 014001 (2015).
  2. H. Homulle, F. Powolny, P. L. Stegehuis, J. Dijkstra, D.-U. Li, K. Homicsko, D. Rimoldi, K. Muehlethaler, J. O. Prior, R. Sinisi, E. Dubikovskaya, E. Charbon and C. Bruschini, Compact solid-state CMOS single-photon detector array for in vivo NIR fluorescence lifetime oncology measurements,
    Biomedical Optics Express (7), pp. 1797-1814 (2016).
  3. H. Homulle, S. Visser, B. Patra, G. Ferrari, E. Prati, C. G. Almudver, K. Bertels, F. Sebastiano and E. Charbon, A Reconfigurable Cryogenic Platform for the Classical Control of Scalable Quantum Computers,
    arXiv preprint (arXiv:1602.05786) (2016).
  4. H. Homulle, S. Visser and E. Charbon, A Cryogenic 1 GSa/s, Soft-Core FPGA ADC for Quantum Computing Applications,
    IEEE Transactions on Circuits and Systems I: Regular Papers (63), pp. 1854-1865 (2016).

Conference proceedings

  1. F. Powolny, K. Homicsko, R. Sinisi, Claudio E. Bruschini, E. Grigoriev, H. Homulle, John O. Prior, D. Hanahan, E. Dubikovskaya and E. Charbon, Time-resolved imaging system for fluorescence-guided surgery with lifetime imaging capability,
    Biophotonics: Photonic Solutions for Better Health Care IV, pp. 912938 (2014).
  2. P. L. Stegehuis, M. C. Boonstra, K. E. de Rooij, F. E. Powolny, R. Sinisi, H. Homulle, C. Bruschini, E. Charbon, C. J. H. van de Velde, B. P. F. Lelieveldt, A. L. Vahrmeijer, J. Dijkstra and M. van de Giessen, Fluorescence lifetime imaging to differentiate bound from unbound ICG-cRGD both in vitro and in vivo,
    Advanced Biomedical and Clinical Diagnostic and Surgical Guidance Systems XIII, pp. 93130O (2015).
  3. H. Homulle, F. Regazzoni and E. Charbon, 200 MS/s ADC implemented in a FPGA employing TDCs,
    Proceedings of the 2015 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays, pp. 228-235 (2015).
  4. S. Visser, H. Homulle and E. Charbon, A 1 GSa/s, Reconfigurable Soft-core FPGA ADC,
    Proceedings of the 2016 ACM/SIGDA International Symposium on Field-Programmable Gate Arrays, pp. 281 (2016).
  5. S. Burri, H. Homulle, C. Bruschini and E. Charbon, LinoSPAD: a time-resolved 256×1 CMOS SPAD line sensor system featuring 64 FPGA-based TDC channels running at up to 8.5 giga-events per second,
    Optical Sensing and Detection IV, pp. 98990D (2016).
  6. H. Homulle, S. Visser, B. Patra, G. Ferrari, E. Prati, C. G. Almudver, K. Bertels, F. Sebastiano and E. Charbon, CryoCMOS hardware technology a classical infrastructure for a scalable quantum computer,
    Proceedings of the ACM International Conference on Computing Frontiers, pp. 282-287 (2016).
Harald Homulle