Younghyun Kim

Open access available Abstract We present the modulation performance optimization process for a depletion-type Si micro-ring modulator (MRM). Our optimization process is based on two different types of model parameters for ring resonator decay time constants derived from the coupled-mode theory. The MRM figure of merit (FOM) is defined for target data rates considering both optical modulation amplitude and the modulation frequency response based on two model parameters. The parametric optimization for modulator output eye diagrams is achieved by analyzing the FOM with MRM simulation with varying two model parameters. In addition, we demonstrate the optimized eye diagram can be achieved with our optimization process and the measurement results agree well with the simulation result.

New publication available! Abstract We propose a novel heat-sinking structure for a high-power broad-area laser diode. In our laser diode, the pedestal structure is introduced to both top and bottom sides of the laser diode so that the heat generated within the device can be more efficiently released. The characteristics of high-power broad-area laser diodes containing the double pedestal structure are numerically analyzed by self-consistent electro-thermal-optical simulation. It is demonstrated that our laser diode has narrower lateral far-field angle and lower active region temperature compared to previously reported high-power laser diode structures. Link1 Link2

It was great to be invited to talk about Si Photonics and my research achievement in Univ. of Tokyo at a seminar held by KOSEAbe (Korean Scientists & Engineers Association in Belgium).

I have started working as an R&D engineer in a Si Photonics group at IMEC which is the world-leading semiconductor R&D consortium since July 2018. More information for IMEC

I finished an alternative military service for 3 years in Korea.  - Seoul Viosys & Seoul Semiconductor (Apr 2015 - Mar 2017)  - Yonsei University (Apr 2017 - May 2018)

Recent published work of depletion-type Si optical modulator with SiGe layer by PETRA and Univ. of Tokyo Congratulations !  Click here to the original web http://iopscience.iop.org/article/10.7567/APEX.11.032201/meta Abstract We developed a high-speed and highly efficient depletion-type Si optical modulator (Si-MOD) with a pn junction by applying a p-type-doped strained SiGe layer, which was stacked on a lateral pn junction-type Si-MOD. We designed an optimum Si-MOD, which is one of the most efficient Si-MODs with a pn junction, and demonstrated highly efficient modulations of 0.67 and 0.81 Vcenterdotcm for V π L at dc reverse bias voltages of −0.5 and −2 Vdc, respectively. We also demonstrated a high-speed operation of 25 Gbps for the Si-MOD at a wavelength of around 1.3 µm.

Talk on Feb 2nd  HP in Palo Alto (Host: Dr. Marco) The talk was mainly based on the work with the title of " Carrier-injection Type Strained SiGe Optical Modulators " which was conducted by Takagi-Takenaka Group in the University of Tokyo.