Investigation on high-speed ring modulators

As increasing demand on high-speedtransceivers for CPO applications, e.g. 400G per lane, we want to look for thesolutions and designs of ring modulator operating beyond 100GHz bandwidth.There is a clear trade-off between efficiency (transmitter penalty, TP) andbandwidth observed [1], but high bandwidth beyond 100GHz ischallenging even if we can sacrifice the efficiency.

We have some designs with low Q-factor ringmodulators (expecting higher BW), so the task of internship will be

1. Verify and measure (if needed)the various ring modulator design for high-speed operation in differentoperating points (e.g. bias, detuning wavelength, etc)
   Required skill: analysis on measured data (Python), understandingof ring odu
2. Characterize and model thefabricated device's performance, and find the limitation of the device wherethe bandwidth limitation comes from
   Required skill: understanding of ring modulator's behavior inmodel (theoretical understanding), fitting the measured data and compare to thetheoretical equation (Python)
3. (If available) Looking for thesolution/design for high-speed ring modulator beyond 100GHz
   Required skill: TCAD, Lumerical simulation for design, Layoutskill if needed

[1] MinkyuKim, Yoojin Ban, Filippo Ferraro, David Coenen, Natarajan Rajasekaran, PeterVerheyen, Rafal Magdziak, Huseyin Sar, Peter De Heyn, Dimitrios Velenis,Philippe Absil, and Joris Van Campenhout, "O-Band Silicon Ring ModulatorsWith Highly Efficient Electro- and Thermo-Optic Modulation," J. LightwaveTechnol. 43, 1328-1334 (2025)

Type of internship: Master internship

Required educational background: Electrotechnics/Electrical Engineering

Supervising scientist(s): For further information or for application, please contact Minkyu Kim ([email protected])

The reference code for this position is 2026-INT-041. Mention this reference code in your application.

Imec allowance will be provided for students studying at a non-Belgian university.

Applications should include the following information:

• resume
• motivation
• current study

Incomplete applications will not be considered.