The main results obtained in the development of the IROCSIM imaging technology are:
- A theoretical framework describing how to generate a sparse optical lattice illumination in a photonic integrated circuit (PIC) with a minimal number of input waveguides. Experimental validation of our optical lattice method was initially obtained using free space optics. Hexagonal, square, and quasi-lattices can be generated and scanned. Published in [1,2], presented at [3,4]. We also explored inverse design methods for the generation of periodic optical patterns in PICs with reduced footprint [5,6].
- Development of an efficient thermo-optic phase shifter and switch matrix in the visible range on a Silicon Nitride platform and a scalable multichannel current source driver. These components are essential for the practical implementation of the interference patterns and to scan them. [7-10].
- Experimental demonstration of structured illumination microscopy (SIM) using our active integrated photonics platform for the generation and modulation of the sinusoidal structured illumination patterns in combination with our custom developed reconstruction algorithm. A resolution of 110 nm was achieved. [11-14]
- A custom fluorescence excitation filter that is placed between the imager and the photonic circuit was developed. This filter rejects the excitation light over a large angular range so that only the fluorescence emission reaches the imager.
- A full fabrication process flow for the monolithic integration of an active photonic integrated circuit with an excitation filter on top of a front-side illuminated (FSI) CMOS imager. [13,14]
- Packaged functional proof-of-concept chips on FSI imager. Chip performance evaluated using fluorescent nanospheres and uniform illumination: image sensor functional; filter performance allows sufficient background suppression resulting in signal-to-noise (SNR) of 30; phase modulators functional; photonic components characterized. [13,14]
- A system model for predicting point-spread function, SNR, resolution. All chip components are included in this model that helps to guide future system design and optimization, and evaluate reconstruction algorithms.
- A compact beam expander with the potential to enable a large field of view. A publication is accepted [15].
- A demo setup to illustrate our on-chip structured illumination microscopy technology at exhibitions. The project team presented this live demo at the tech exhibition of the imec Future summits 2022 in Antwerp.
1) D. Kouznetsov, et al. Phys Rev Lett 125, (2020).
2) D. Kouznetsov, et al. Phys Rev A 105, (2022).
3) D. Kouznetsov et al. Biophotonics and Imaging Graduate Summer School (BIGGS, 2020)
4) D. Kouznetsov, et al. Complex Light and Optical Forces XV vol. 11701 1170117 (SPIE Photonics West, 2021).
5) D. Kouznetsov, et al. Optics Express 30(7), (2022).
6) D. Kouznetsov, et al. Proceedings Optica Advanced Photonics Congress 2022 IW5B.4 (2022)
7) Q. Deng, et al. Integrated Photonics Platforms: Fundamental Research, Manufacturing and Applications vol. 11364 52 (SPIE Photonics Europe, 2020).
8) Q. Deng, et al. Asia Communications and Photonics Conference/International Conference on Information Photonics and Optical Communications 2020 (ACP/IPOC) T4D.2 (2020).
9) Q. Deng, et al. China Semiconductor Technology International Conference (CSTIC) (2020)
10) N. Verellen, et al. European conference on integrated optics (ECIO, 2020) & O. Arisev, et al. Biophotonics and Imaging Graduate Summer School (BIGGS, 2020)
11) O. Arisev et al. ICON Europe 2021 – 3rd international conference on nanoscopy (2021)
12) O. Arisev, et al. Proceedings Optica Advanced Photonics Congress 2022 ITu1B.5 (2022).
13) N. Verellen, et al. 4th International Conference on Optics Photonics and Lasers (2023)
14) P. Van Dorpe, et al. SPIE Photonics West (2024)
15) D. Kouznetsov, et al. Journal of Optics (accepted 2024)
