Jocelyn N. Westwood‐Bachman

Applied Nanotools (Canada)

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Wayne K. Hiebert

National Research Council Canada

Cameron Horvath

Applied Nanotools (Canada)

Mirwais Aktary

Applied Nanotools (Canada)

Vincent T. K. Sauer

Nordion (Canada)

Cameron M. Naraine

McMaster University

Anandram Venkatasubramanian

University of Michigan–Ann Arbor

Jonathan D. B. Bradley

McMaster University

Jens H. Schmid

National Research Council Canada

Pavel Cheben

National Research Council Canada

Martin D. Dawson

University of Strathclyde

Cooperative Institutions

University of Alberta

McMaster University

University of British Columbia

National Institute for Nanotechnology

National Research Council Canada

Massachusetts Institute of Technology

University of California, San Diego

SUNY Polytechnic Institute

Université Laval

Georgia Institute of Technology

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Improving mechanical sensor performance through larger damping

Science (2018)

Swapan K. Roy Vincent T. K. Sauer Jocelyn N. Westwood‐Bachman Anandram Venkatasubramanian Wayne K. Hiebert

Mechanical resonances are used in a wide variety of devices, from smartphone accelerometers to computer clocks and from wireless filters to atomic force microscopes. Frequency stability, a critical performance metric, is generally assumed to be tantamount to resonance quality factor (the inverse of the linewidth and of the damping). We show that the frequency stability of resonant nanomechanical sensors can be improved by lowering the quality factor. At high bandwidths, quality-factor reduction is completely mitigated by increases in signal-to-noise ratio. At low bandwidths, notably, increased damping leads to better stability and sensor resolution, with improvement proportional to damping. We confirm the findings by demonstrating temperature resolution of 60 microkelvin at 300-hertz bandwidth. These results open the door to high-performance ultrasensitive resonators in gaseous or liquid environments, single-cell nanocalorimetry, nanoscale gas chromatography, atmospheric-pressure nanoscale mass spectrometry, and new approaches in crystal oscillator stability.

Q factor

Laser linewidth

Tuning fork

Nanomechanics

10.1126/science.aar5220

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Citations (71)

Porous Nanophotonic Optomechanical Beams for Enhanced Mass Adsorption

ACS Sensors (2019)

Anandram Venkatasubramanian Vincent T. K. Sauer Jocelyn N. Westwood‐Bachman Kai Cui Mike Xia

We have developed a porous silicon nanocantilever for a nano-optomechanical system (NOMS) with a universal sensing surface for enhanced sensitivity. Using electron beam lithography, we selectively applied a V2O5/HF stain etch to the mechanical elements while protecting the silicon-on-insulator photonic ring resonators. This simple, rapid, and electrodeless approach generates tunable device porosity simultaneously with the mechanical release step. By controlling the porous etchant concentration and etch time, the porous etch depth, resonant frequency, and the adsorption surface area could be precisely manipulated. Using this control, cantilever sensors ranging from nonporous to fully porous were fabricated and tested as gas-phase mass sensors of volatile organic compounds coming from a gas chromatography stream. The fully porous cantilever produced a dramatic 10-fold increase in sensing signal and a 6-fold improvement in limit of detection (LOD) compared to an otherwise identical nonporous cantilever. This signal improvement could be separated into mass responsivity increase and adsorption increase components. Allan deviation measurements indicate that a further 4-fold improvement in LOD could be expected upon speeding up characteristic peak response time from 1 s to 50 ms. These results show promise for performance enhancement in nanomechanical sensors for applications in gas sensing, gas chromatography, and mass spectrometry.

Porous Silicon

10.1021/acssensors.8b01366

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Citations (5)

Efficient actuation design for optomechanical sensors

Optics Express (2020)

Jocelyn N. Westwood‐Bachman Timothy S. Lee Wayne K. Hiebert

For any nanomechanical device intended for sensing applications, actuation is an important consideration. Many different actuation mechanisms have been used, including self-oscillation, piezoelectric shakers, capacitive excitation, and optically pumping via the optical gradient force. Despite the relatively frequent use of optical pumping, the limits of optical actuation with a pump laser have not been fully explored. We provide a practical framework for designing optical cavities and optomechanical systems to maximize the efficiency of the optical pumping technique. The effects of coherent backscattering on detection and actuation are included. We verify our results experimentally and show good agreement between the model and experiment. Our model for efficient actuation will be a useful resource for the future design of optomechanical cavities for sensor and other high-amplitude applications.

Optical force

Optomechanics

Oscillation (cell signaling)

10.1364/oe.403602

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Citations (1)

Resonant spatial light modulation with wafer-scale, inverse-designed microcavity arrays

Conference on Lasers and Electro-Optics (2022)

Christopher Panuski Ian Christen Sivan Trajtenberg Mills Cole Brabec Momchil Minkov

We present inverse-designed arrays of vertically-coupled, high-finesse, wavelength-scale photonic crystal cavities in a commercial foundry. Dynamically controlling each pixel with a high-speed (~100 MHz) µLED display enables efficient spatial light modulation with unprecedented spatiotemporal bandwidth.

Modulation (music)

Finesse

Wafer-scale integration

10.1364/cleo_si.2022.sm4p.1

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Citations (0)

Prototyping of silicon nitride photonic integrated circuits for visible and near-infrared applications

Cameron Horvath Jocelyn N. Westwood‐Bachman Kevin Setzer Alexandria McKinlay Cameron M. Naraine

We describe a prototyping process for silicon nitride photonic integrated circuits, targeting applications in the visible and near-infrared wavelength ranges. The platform is based on direct-write electron beam lithography technology and provides a route toward the rapid fabrication of passive and thermo-optic active photonic devices. The fabrication turnaround time is on the order of several weeks, and critical feature sizes are demonstrated down to 100 nm which enables the fabrication of subwavelength metastructures. Two waveguiding material thicknesses have been demonstrated, 150 nm for visible light applications and 400 nm for infrared.

10.1117/12.2647576

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Citations (0)

Improving mechanical sensor performance through larger damping

arXiv (Cornell University) (2017)

Swapan K. Roy Vincent T. K. Sauer Jocelyn N. Westwood‐Bachman Anandram Venkatasubramanian Wayne K. Hiebert

Mechanical resonances are used in a wide variety of devices; from smart phone accelerometers to computer clocks and from wireless communication filters to atomic force microscope sensors. Frequency stability, a critical performance metric, is generally assumed to be tantamount to resonance quality factor (the inverse of the linewidth and of the damping). Here we show that frequency stability of resonant nanomechanical sensors can generally be made independent of quality factor. At high bandwidths, we show that quality factor reduction is completely mitigated by increases in signal to noise ratio. At low bandwidths, strikingly, increased damping leads to better stability and sensor resolution, with improvement proportional to damping. We confirm the findings by demonstrating temperature resolution of 50 \mu K at 200 Hz bandwidth. These results open the door for high performance ultrasensitive resonant sensors in gaseous or liquid environments, single cell nanocalorimetry, nanoscale gas chromatography, and atmospheric pressure nanoscale mass spectrometry.

Laser linewidth

Q factor

Source

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Citations (0)

Permanent Phase Correction in a Polarization Diversity Si PIC by Femtosecond Laser Pulses

IEEE Photonics Technology Letters (2015)

Daniel Bachman Zhijiang Chen Jocelyn N. Westwood‐Bachman Wayne K. Hiebert Y. Painchaud

We report a fast and efficient method for permanently correcting fabrication-induced phase errors in silicon photonic circuits. The method uses femtosecond laser pulses at 400-nm wavelength to amorphize a thin layer of crystalline silicon near the waveguide surface, thereby inducing a change in the effective index of the waveguide. Using a single femtosecond laser pulse, we reduced the polarization-dependent frequency shift between the two interferometers of a polarization diversity differential phase shift keying silicon demodulator from 11 GHz to less than 0.5 GHz, thereby restoring the polarization diversity operation of the circuit with little degradation to the circuit performance.

Waveguide

10.1109/lpt.2015.2444394

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Citations (5)

Improving mechanical sensor performance through larger damping

arXiv (Cornell University) (2017)

Swapan Kumar Roy Vincent T. K. Sauer Jocelyn N. Westwood‐Bachman Anandram Venkatasubramanian Wayne K. Hiebert

Laser linewidth

Q factor

10.48550/arxiv.1710.11280

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Citations (0)

Silicon Nitride Ring Resonators Based on Subwavelength Grating Metamaterials

Conference on Lasers and Electro-Optics (2022)

Cameron M. Naraine Jocelyn N. Westwood‐Bachman Cameron Horvath Mirwais Aktary Andrew P. Knights

We demonstrate subwavelength grating metamaterial ring resonators on a silicon nitride platform. We report an internal Q factor of 2.11˖10 5 and 1.48 dB/cm propagation loss at 1540 nm wavelength. We discuss the potential of these novel devices for applications in evanescent field sensing and light amplification.

Split-ring resonator

Optical ring resonators

Q factor

10.1364/cleo_si.2022.sth2h.3

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Determination of the nonlinear thermo-optic coefficient of silicon nitride and oxide using an effective index method

Optics Express (2022)

Karl Johnson Naif Alshamrani Dhaifallah Almutairi Andrew Grieco Cameron Horvath

There is little literature characterizing the temperature-dependent thermo-optic coefficient (TOC) for low pressure chemical vapor deposition (LPCVD) silicon nitride or plasma enhanced chemical vapor deposition (PECVD) silicon dioxide at temperatures above 300 K. In this study, we characterize these material TOC's from approximately 300-460 K, yielding values of (2.51 ± 0.08) · 10-5K-1 for silicon nitride and (5.67 ± 0.53) · 10-6K-1 for silicon oxide at room temperature (300 K). We use a simplified experimental setup and apply an analytical technique to account for thermal expansion during the extraction process. We also show that the waveguide geometry and method used to determine the resonant wavelength have a substantial impact on the precision of our results, a fact which can be used to improve the precision of numerous ring resonator index sensing experiments.

Silicon oxide

Silicon dioxide

Waveguide

10.1364/oe.477102

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Citations (8)