Publications de Nils Johan Engelsen

Motional Sideband Asymmetry of a Solid-State Mechanical Resonator at Room Temperature

Tobias Kippenberg, Nils Johan Engelsen, Alberto Beccari, Amirali Arabmoheghi, Guanhao Huang

The motional sideband asymmetry of a mechanical oscillator interacting with a laser field can be observed when approaching the quantum ground state, where the zero-point energy of the mechanical oscillator becomes a sizable contribution to its motion. In t ...

2025

Ultrahigh-quality-factor micro- and nanomechanical resonators using dissipation dilution

Tobias Kippenberg, Nils Johan Engelsen, Alberto Beccari

Mechanical resonators are widely used in sensors, transducers and optomechanical systems, where mechanical dissipation sets the ultimate limit to performance. Over the past 15 years, the quality factors in strained mechanical resonators have increased by f ...

Nature Portfolio2024

Room-temperature quantum optomechanics using an ultralow noise cavity

Tobias Kippenberg, Nils Johan Engelsen, Alberto Beccari, Guanhao Huang

At room temperature, mechanical motion driven by the quantum backaction of light has been observed only in pioneering experiments in which an optical restoring force controls the oscillator stiffness1,2. For solid-state mechanical resonators in which oscil ...

Nature Portfolio2024

Framework of Free-Electron Quantum Optics Using Photonic Integrated Circuits

Tobias Kippenberg, Nils Johan Engelsen, Guanhao Huang

We develop a framework of using photonic integrated circuits for free-electron quantum optics applications. We formulate the interaction using a three-dimensional QED quantization procedure, and discuss a few fundamental limitations and specific applicatio ...

Optical Society of America2023

Ultralow Dissipation Mechanical Resonators for Cavity-Free Quantum Control

Tobias Kippenberg, Nils Johan Engelsen, Alberto Beccari, Amirali Arabmoheghi, Guanhao Huang

We fabricate nanomechanical resonators with Q > 109 at room temperature and show efficient optical readout of their motion. With an improved interferometer, these devices can be cooled close to the ground state without a cavity. ...

Optical Society of America2023

Perimeter Modes of Nanomechanical Resonators Exhibit Quality Factors Exceeding 10(9) at Room Temperature

Tobias Kippenberg, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari, Amirali Arabmoheghi, Guanhao Huang

Systems with low mechanical dissipation are extensively used in precision measurements such as gravitational wave detection, atomic force microscopy, and quantum control of mechanical oscillators via optomechanics and electromechanics. The mechanical quali ...

American Physical Society2022

Strained crystalline nanomechanical resonators with quality factors above 10 billion

Tobias Kippenberg, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari

In strained mechanical resonators, the concurrence of tensile stress and geometric nonlinearity dramatically reduces dissipation. This phenomenon, called dissipation dilution, is employed in mirror suspensions of gravitational-wave interferometers and at t ...

NATURE PORTFOLIO2022

Hierarchical tensile structures with ultralow mechanical dissipation

Tobias Kippenberg, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari, Amirali Arabmoheghi

Structural hierarchy is found in myriad biological systems and has improved man-made structures ranging from the Eiffel tower to optical cavities. In mechanical resonators whose rigidity is provided by static tension, structural hierarchy can reduce the di ...

Nature Portfolio2022

High-yield, wafer-scale fabrication of ultralow-loss, dispersion-engineered silicon nitride photonic circuits

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Arslan Sajid Raja, Nils Johan Engelsen, Guanhao Huang, Jijun He, Tianyi Liu

Low-loss photonic integrated circuits and microresonators have enabled a wide range of applications, such as narrow-linewidth lasers and chip-scale frequency combs. To translate these into a widespread technology, attaining ultralow optical losses with est ...

Nature Research2021

A high-cooperativity, nano-optomechanical system comprised of high stress Si3N4

Tobias Kippenberg, Nils Johan Engelsen, Amirali Arabmoheghi

We report the design fabrication and characterization of a monolithic nano-optomechanical transducer comprised of high stress silicon nitride (Si3N4). Our system features a one dimensional Fabry-Perot photonic crystal cavity (Q approximate to 10(5)) integr ...

IEEE2021

A High Cooperativity Silicon Nitride Optomechanical Transducer

Tobias Kippenberg, Nils Johan Engelsen, Amirali Arabmoheghi

IEEE2021

High-yield, wafer-scale fabrication of ultralow-loss, dispersion-engineered silicon nitride photonic circuits

Rui Ning Wang, Tobias Kippenberg, Junqiu Liu, Arslan Sajid Raja, Nils Johan Engelsen, Guanhao Huang, Jijun He

IEEE2021

Fractal-like Mechanical Resonators with a Soft-Clamped Fundamental Mode

Tobias Kippenberg, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari

Self-similar structures occur naturally and have been employed to engineer exotic physical properties. We show that acoustic modes of a fractal-like system of tensioned strings can display increased mechanical quality factors due to the enhancement of diss ...

AMER PHYSICAL SOC2020

Wafer-scale fabrication of ultralow-loss silicon nitride nonlinear photonic circuits

Rui Ning Wang, Tobias Kippenberg, Maxim Karpov, Junqiu Liu, Miles Henry Anderson, Arslan Sajid Raja, Nils Johan Engelsen, Wenle Weng, Anton Lukashchuk, Guanhao Huang, Jijun He, Mikhail Churaev, Anat Siddharth, Alexey Tikan

Recent advances in silicon nitride integrated photonics have achieved ultralow optical losses. Transferring this technology to standard commercial foundries, and merging it with silicon photonics via heterogeneous integration, will seed novel laser and qua ...

IEEE2020

Thermo-refractive noise in silicon nitride microresonators

Tobias Kippenberg, Erwan Guillaume Albert Lucas, Junqiu Liu, Arslan Sajid Raja, Nils Johan Engelsen, Guanhao Huang

Thermodynamic noises limit the frequency stability of resonators. Here, we present the first complete characterization of thermo-refractive noise in Si3N4 microresonators. The measurements are in good agreement with theoretical analysis and FEM simulation ...

IEEE2019

Photonic Integrated K-Band Microwave Oscillator Based on Silicon Nitride Soliton Microcomb

Rui Ning Wang, Tobias Kippenberg, Erwan Guillaume Albert Lucas, Maxim Karpov, Hairun Guo, Junqiu Liu, Arslan Sajid Raja, Nils Johan Engelsen, Guanhao Huang, Jijun He

Using photonic integrated silicon nitride microresonators of quality factor exceeding 15 million, we demonstrate 19-GHz-repetition-rate single soliton with 35 mW optical power, and characterize the phase noise of the repetition rate in the K-band microwave ...

IEEE2019

Ultralow-power chip-based soliton microcombs for photonic integration

Michail Zervas, Tobias Kippenberg, Martin Hubert Peter Pfeiffer, Maxim Karpov, Hairun Guo, Bahareh Ghadiani, Junqiu Liu, Arslan Sajid Raja, Nils Johan Engelsen, Anton Lukashchuk

Using the photonic Damascene reflow process, we present single soliton formation in 99-GHz-FSR Si3N4 microresonators of Q-factor exceeding 15 x 10(6), with less than 10 mW optical power. ...

IEEE2019

Ultralow Dissipation Mechanical Resonators for Quantum Optomechanics

Tobias Kippenberg, Amir Hossein Ghadimi, Ryan Daniel Schilling, Dalziel Joseph Wilson, Sergey Fedorov, Nils Johan Engelsen, Alberto Beccari

We demonstrate dissipation dilution engineering techniques for ultralow dissipation mechanical resonators. The Si3N4 nanobeams show quality factors (Q) as high as 800 million and Q x f exceeding 10(15) Hz-both records at room temperature. (C) 2019 The Auth ...

IEEE2019

Generalized dissipation dilution in strained mechanical resonators

Tobias Kippenberg, Amir Hossein Ghadimi, Ryan Daniel Schilling, Dalziel Joseph Wilson, Sergey Fedorov, Nils Johan Engelsen

Mechanical resonators with high quality factors are widely used in precision experiments, ranging from gravitational wave detection and force sensing to quantum optomechanics. Beams and membranes are well known to exhibit flexural modes with enhanced quali ...

AMER PHYSICAL SOC2019

Thermorefractive noise in silicon-nitride microresonators

Tobias Kippenberg, Erwan Guillaume Albert Lucas, Junqiu Liu, Arslan Sajid Raja, Nils Johan Engelsen, Guanhao Huang

Thermodynamic noise places a fundamental limit on the frequency stability of dielectric optical resonators. Here, we present the characterization of thermorefractive noise in photonic-chip-based silicon-nitride (Si3N4) microresonators and show that thermor ...

AMER PHYSICAL SOC2019