Publications by Xinru Ji | EPFL Graph Search

C- and L-band tunable integrated Erbium lasers via scalable manufacturing

Tobias Kippenberg, Xinru Ji, Zheru Qiu, Grigorii Likhachev, Andrey Voloshin

We demonstrate an integrated Erbium-based tunable laser using wafer-scale fabrication and ion implantation of silicon nitride photonic integrated circuits. We achieve single-frequency lasing tunable from 1530 nm to 1621 nm covering nearly the entire optica ...

Optica Publishing Group2025

High-Energy Mode-Locked Pulses from a Photonic Integrated Mamyshev Oscillator

Tobias Kippenberg, Jianqi Hu, Xinru Ji, Zheru Qiu, Grigorii Likhachev, Zihan Li

Mode-locked lasers (MLLs), capable of generating ultrashort coherent pulses, have been instrumental for numerous applications, including optical frequency metrology, eye surgery, machining, additive manufacturing, imaging and spectroscopy. However, commerc ...

IEEE2025

Silicon nitride waveguide or photonic integrated circuit fabrication method

Tobias Kippenberg, Xinru Ji

Silicon nitride waveguide fabrication method including providing a substrate including a stress release trench structure, the stress release recess structure being formed in a silicon oxide layer, depositing a silicon nitride material or layer onto the sil ...

2024

Sub-MHz linewidth, FMCW photonic integrated blue laser

Tobias Kippenberg, Anat Siddharth, Xinru Ji

We demonstrate for the first time a frequency-modulated continuous wave photonic integrated blue laser with sub-MHz linewidth. The laser exhibits frequency excursion greater than 900 MHz at up to 1 MHz triangular chirp rate with a nonlinearity of less than ...

Institute of Electrical and Electronics Engineers Inc.2024

Photonic substrate preparation method and photonic waveguide preparation or fabrication method

Tobias Kippenberg, Xinru Ji, Zheru Qiu

Photonic integrated circuit optical waveguide device preparation or fabrication method comprising providing a silicon substrate, depositing at least one copper gettering silicon nitride layer or material, depositing at least one optical waveguide cladding ...

2024

A fully hybrid integrated erbium-based laser

Tobias Kippenberg, Rui Ning Wang, Xinru Ji, Zheru Qiu, Andrea Bancora, Andrey Voloshin

Erbium-doped fibre lasers exhibit high coherence and low noise as required for fibre-optic sensing, gyroscopes, LiDAR and optical frequency metrology. Endowing erbium-based gain in photonic integrated circuits can provide a basis for miniaturizing low-nois ...

Nature Publishing Group2024

Lithium tantalate photonic integrated circuits for high volume manufacturing

Tobias Kippenberg, Mikhail Churaev, Xinru Ji, Zihan Li

We demonstrate the first photonic integrated circuit platform using Lithium Tantalate (LiTaO3), achieving waveguides with low losses (5.6 dB m−1), Mach-Zehnder modulators with a 40 GHz electro-optical bandwidth and a 1.96 V · cm voltage-length product, alo ...

Institute of Electrical and Electronics Engineers Inc.2024

Foundry compatible, efficient wafer-scale manufacturing of ultra-low loss, high-density Si3N4 photonic integrated circuits

Tobias Kippenberg, Rui Ning Wang, Xinru Ji, Zheru Qiu

We demonstrate ultra-low propagation loss, lithographic precision, and wafer-scale manufacturing for high-density Si3N4 photonic integrated circuits using an efficient DUV-based subtractive approach. We show a propagation loss as low as 1.4 dB/m at 1.55 µm ...

Optical Society of America2024

Photonic-electronic integrated circuit-based coherent LiDAR engine

Edoardo Charbon, Tobias Kippenberg, Xinru Ji, Zheru Qiu, Grigorii Likhachev, Halil Kerim Yildirim, Andrea Bancora, Anton Lukashchuk, Andrey Voloshin

Chip-scale integration is a key enabler for the deployment of photonic technologies. Coherent laser ranging or FMCW LiDAR, a perception technology that benefits from instantaneous velocity and distance detection, eye-safe operation, long-range, and immunit ...

Nature Portfolio2024

Efficient mass manufacturing of high-density, ultra-low-loss Si3N4 photonic integrated circuits

Tobias Kippenberg, Rui Ning Wang, Xinru Ji, Zheru Qiu

Silicon nitride (Si3N4) photonic integrated circuits (PICs) offer significant advantages over traditional silicon photonics, including low loss and superior power handling at optical communication wavelength bands. To facilitate high-density integration an ...

2024