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PhD position: Thermal management co-package optics for Si photonic applications

PhD position: Thermal management co-package optics for Si photonic applications

This PhD topic is a collaboration between the Reliability and Modeling Research group in imec ( and the Thermal and Fluids Engineering Research group of KULeuven (

The requirements for package-to-package input-output (I/O) interfaces in future high-performance computing systems scale up to multiple Terabytes per second. The traditional scaling of I/O's using electrical links for data transmission faces many bottlenecks such as pin count and bandwidth-distance-power trade-off. The advantages of Si photonics, very high bandwidth and low propagation loss and delay, allow the implementation of in-package optical transceiver modules with a direct interface to CMOS chips by using integrated silicon photonics modulators and detectors. Recent advanced packaging technologies allow the tight integration of Si photonics transceiver technology with the host IC in a single chip package. These co-packaged optics enable the high bandwidth required for future data centers as well as the reduction of the package footprint. The Si photonic elements are however significantly affected by changes in local and ambient temperature variations, e.g. caused by the highly
non-uniform power generation in the ASIC or FPGA CMOS chip, the laser sources, and the optical devices themselves. Temperature changes can cause a wavelength shift which leads to an optical power loss due to wavelength mismatch and to laser power degradation, which introduces more challenges for the thermal management of these co-packaged optics. The objective of this PhD is to address the fundamental thermal management challenges for these integrated packages that contain a high-power host IC (FPGA or ASIC), Si photonics chips with integrated silicon photonics modulators and detectors and memory modules (HBM or HMC).

In this PhD work, the following activities are foreseen:
* Modeling of the thermal behavior of the integrated package. This tasks research involves the development of a multi-scale modeling framework to couple the electrical, thermal and optical fields in order to assess the extent of the thermal impact on the optical link between laser, modulator, waveguide and detector. The modeling scales range from the cm-level, including the chip package and the impact of the cooling solution and boundary conditions, down to the ┬Ám-level of the integrated optical devices.
* Identification of the cooling needs and constraints for the cooling solutions of test cases for the integrated packages.
* Development of a demonstrator of the cooling solution on a test vehicle for the validation of the developed model and for the thermal and optical characterization of the system.

* Master degree in engineering, physics or mathematics.
* Proficient in written and spoken English.
* Affinity with numerical methods.

Full time PhD position for 4 yours.

At imec, more than 700 PhD students from over 40 different countries are working on the future of a better world. This is possible thanks to imec partnerships with universities all around the world.

We offer you the opportunity to join one of the world's premier research centers in nanotechnology at its headquarters in the vibrant and international city of Leuven in Belgium. Here is why a PhD at imec is a unique opportunity:
* Work in an inspiring, multidisciplinary & international environment.
* Enhance competitiveness with our in-depth technology knowledge.
* Develop your skills through specialized technical training.
* Get in touch with imec's global international partner companies.
* Gain access to state-of-the-art infrastructure.
* Use our large international network of expertise.


KU Leuven - Universiteit

PhD position: Thermal management co-package optics for Si photonic applications

KU Leuven, Leuven
Project Manager
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