Determination of the quasi-TE mode (in-plane) graphene linear absorption coefficient via integration with silicon-on-insulator racetrack cavity resonators

Crowe, Iain F.; Clark, Nick; Hussein, Siham Mohamed Ahmed; Towlson, Brian; Whittaker, E. J. W.; Milošević, Milan; Gardes, Frederic Y.; Mashanovich, Goran Z.; Halsall, Matthew P.; Vijayaraghaven, Aravind

doi:10.1364/oe.22.018625

Cited by 8 publications

(5 citation statements)

References 25 publications

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“…The quality factor (λ/Δλ) of the MRR cavity resonance decreases from ~9000 to ~7500 after GO deposition. This relatively small change suggests that the absorption of light by the GO is not as strong as for graphene 33,36 , which is a key aspect for a functional layer for MRR based gas or vapour sensing, where a high quality factor is preferred, for a given detection resolution, in order to be able to measure relatively small shifts in the resonant wavelength.…”

Section: Resultsmentioning

confidence: 99%

Graphene oxide integrated silicon photonics for detection of vapour phase volatile organic compounds

Tsui

Mao

Alodhayb

et al. 2020

Sci Rep

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the optical response of a graphene oxide integrated silicon micro-ring resonator (GoMRR) to a range of vapour phase Volatile organic compounds (Vocs) is reported. the response of the GoMRR to all but one (hexane) of the VOCs tested is significantly higher than that of the uncoated (control) silicon MRR, for the same vapour flow rate. An iterative Finite Difference Eigenmode (FDE) simulation reveals that the sensitivity of the GO integrated device (in terms of RIU/nm) is enhanced by a factor of ~2, which is coupled with a lower limit of detection. critically, the simulations reveal that the strength of the optical response is determined by molecular specific changes in the local refractive index probed by the evanescent field of the guided optical mode in the device. Analytical modelling of the experimental data, based on Hill-Langmuir adsorption characteristics, suggests that these changes in the local refractive index are determined by the degree of molecular cooperativity, which is enhanced for molecules with a polarity that is high, relative to their kinetic diameter. We believe this reflects a molecular dependent capillary condensation within the graphene oxide interlayers, which, when combined with highly sensitive optical detection, provides a potential route for discriminating between different vapour phase VOCs.

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Section: Resultsmentioning

confidence: 99%

Graphene oxide integrated silicon photonics for detection of vapour phase volatile organic compounds

Tsui

Mao

Alodhayb

et al. 2020

Sci Rep

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“…Compared with evanescent-wave devices based on microfibers, waveguide-integrated devices offer smaller footprints. Crowe et al [32] studied light-matter interactions in graphene-based silicon-on-insulator (SOI) racetrack cavity resonators and by optimizing the thickness of the separation spacer layer between graphene and the waveguide, the maximum sensitivity can be achieved. Lim et al [33] demonstrated a humidity sensor by integrating GO on the SU-8 waveguide.…”

Section: Waveguide-integrated Graphene Photonic Devices For Sensing Amentioning

confidence: 99%

Recent Progress in Waveguide-Integrated Graphene Photonic Devices for Sensing and Communication Applications

et al. 2020

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Graphene is a two-dimensional material with numerous intriguing optical properties, such that graphene photonic devices have attracted great interest for sensing and communication applications. However, surface-illuminated graphene photonic devices usually suffer from weak light-matter interactions due to the atomic-layer thickness of graphene, seriously limiting the performances of such devices. To tackle this problem, waveguide-integrated graphene photonic devices have been demonstrated since 2010, which offer the advantage of much longer interaction length between the evanescent field of the optical waveguide and graphene than the surface-illuminated devices. Moreover, the fabrication of waveguide-integrated graphene photonic devices is compatible with CMOS technology, allowing potentially low-cost and high-density on-chip integration. To date, a tremendous interest is growing in the hybrid integration platform composed of graphene and silicon photonic integrated circuits. In this paper, we review the recent progress in waveguide-integrated graphene photonic devices and their applications in sensing and communication.

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“…This may be overcome, at least in part, by using slotted, concentric- [6,7], cascaded- [8] or subwavelength-grating (SWG)-RRs [9] or by the integration of functional layers, capable of better adsorbing or chemically activating, surface-bound molecular analytes. In some cases, such approaches were also reported to provide a degree of selectivity [10][11][12].…”

Section: Introductionmentioning

confidence: 99%

A Design of a Novel Silicon Photonics Sensor with Ultra-Large Free Spectral Range Based on a Directional Coupler-Assisted Racetrack Resonator (DCARR)

Crowe

2023

Sensors

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A novel refractive index-based sensor implemented within a silicon photonic integrated circuit (PIC) is reported. The design is based on a double-directional coupler (DC) integrated with a racetrack-type resonator (RR) to enhance the optical response to changes in the near-surface refractive index via the optical Vernier effect. Although this approach can give rise to an extremely large ‘envelope’ free spectral range (FSRVernier), we restrict the design geometry to ensure this is within the traditional silicon PIC operating wavelength range of 1400–1700 nm. As a result, the exemplar double DC-assisted RR (DCARR) device demonstrated here, with FSRVernier = 246 nm, has a spectral sensitivity SVernier = 5 × 104 nm/RIU.

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Determination of the quasi-TE mode (in-plane) graphene linear absorption coefficient via integration with silicon-on-insulator racetrack cavity resonators

Cited by 8 publications

References 25 publications

Graphene oxide integrated silicon photonics for detection of vapour phase volatile organic compounds

Graphene oxide integrated silicon photonics for detection of vapour phase volatile organic compounds

Recent Progress in Waveguide-Integrated Graphene Photonic Devices for Sensing and Communication Applications

A Design of a Novel Silicon Photonics Sensor with Ultra-Large Free Spectral Range Based on a Directional Coupler-Assisted Racetrack Resonator (DCARR)

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