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S Janz,
D-X Xu, M Vachon,
N Sabourin,
P Cheben,
H McIntosh,
H Ding,
S Wang,
J H Schmid,
A Delâge, [......],
R Ma,
W Sinclair,
S M Logan,
R Mackenzie,
Q Y Liu,
D Zhang,
G Lopinski,
O Mozenson,
M Gilmour,
H Tabor
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ABSTRACT: A complete photonic wire molecular biosensor microarray chip architecture and supporting instrumentation is described. Chip layouts with 16 and 128 independent sensors have been fabricated and tested, where each sensor can provide an independent molecular binding curve. Each sensor is 50 μm in diameter, and consists of a millimeter long silicon photonic wire waveguide folded into a spiral ring resonator. An array of 128 sensors occupies a 2 × 2 mm<sup>2</sup> area on a 6 × 9 mm<sup>2</sup> chip. Microfluidic sample delivery channels are fabricated monolithically on the chip. The size and layout of the sensor array is fully compatible with commercial spotting tools designed to independently functionalize fluorescence based biochips. The sensor chips are interrogated using an instrument that delivers sample fluid to the chip and is capable of acquiring up to 128 optical sensor outputs simultaneously and in real time. Coupling light from the sensor chip is accomplished through arrays of sub-wavelength surface grating couplers, and the signals are collected by a fixed two-dimensional detector array. The chip and instrument are designed so that connection of the fluid delivery system and optical alignment are automated, and can be completed in a few seconds with no active user input. This microarray system is used to demonstrate a multiplexed assay for serotyping E. coli bacteria using serospecific polyclonal antibody probe molecules.
Optics Express 02/2013; 21(4):4623-4637. · 3.59 Impact Factor
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A. V. Velasco,
M. L. Calvo,
P. Cheben,
A. Ortega-Moñux,
J. H. Schmid,
C. Alonso Ramos,
Í. Molina Fernandez,
J. Lapointe, M. Vachon,
S. Janz,
D.-X. Xu
[show abstract]
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ABSTRACT: The design and fabrication of an ultracompact silicon-on-insulator polarization converter is reported. The polarization conversion with an extinction ratio of 16 dB is achieved for a conversion length of only 10 μm. Polarization rotation is achieved by inducing a vertical asymmetry by forming in the waveguide core two subwavelength trenches of different depths. By taking advantage of the calibrated reactive ion etch lag, the two depths are implemented using a single mask and etching process. The measured converter loss is −0.7 dB and the 3 dB bandwidth is 26 nm.
Optics Letters 01/2012; 37:365-367. · 3.40 Impact Factor
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D. Xu,
A. Densmore,
P. Cheben, M. Vachon,
R. Ma,
S. Janz,
A. Delâge,
J.H. Schmid,
J. Lapointe,
Y. Li,
G. Lopinski,
R. Halir,
I. Molina-Fernandez
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ABSTRACT: We review our work on silicon wire devices designed for evanescent field sensor arrays and ultra-compact dense optical comb filters, both taking advantage of a spiral cavity resonator design. Two sensor array configurations are described, and monitoring of biomolecular binding is demonstrated with a detection limit of 0.3 pg/mm<sup>2</sup>. On-chip temperature drift compensation is achieved by using a reference resonator. A novel grating coupler using subwavelength structures facilitates the coupling of light between the optical fiber and waveguide chips.
Communications and Photonics Conference and Exhibition (ACP), 2010 Asia; 01/2011
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J. Saunders,
M.A. Dreher,
J.A. Barnes,
C.M. Crudden,
J. Du,
H. Loock,
Dan-Xia Xu,
A. Densmore,
R. Ma,
S. Janz, M. Vachon,
J. Lapointe,
A. Delage,
J. Schmid,
P. Cheben
[show abstract]
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ABSTRACT: Micro-photonic SOI Mach-Zehnder interferometers were coated with solid-phase micro-extraction materials derived from polydimethylsiloxane to enable sensing of volatile organic compounds of the BTEX class in air. A different coating based on functionalized mesoporous silicates is used to detect lead Pb(II) with a detection limit of <;; 100 ppb in water.
Group IV Photonics (GFP), 2010 7th IEEE International Conference on; 10/2010
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D-X Xu, M Vachon,
A Densmore,
R Ma,
S Janz,
A Delâge,
J Lapointe,
P Cheben,
J H Schmid,
E Post,
Sonia Messaoudène,
Jean-Marc Fédéli
[show abstract]
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ABSTRACT: A comprehensive investigation of real-time temperature-induced resonance shift cancellation for silicon wire based biosensor arrays is reported for the first time. A reference resonator, protected by either a SU8 or SiO(2) cladding layer, is used to track temperature changes. The temperature dependence of resonators in aqueous solutions, pertinent to biosensing applications, is measured under steady-state conditions and the operating parameters influencing these properties are discussed. Real-time measurements show that the reference resonator resonances reflect the temperature changes without noticeable time delay, enabling effective cancellation of temperature-induced shifts. Binding between complementary IgG protein pairs is monitored over 4 orders of magnitude dynamic range down to a concentration of 20 pM, demonstrating a resolvable mass of 40 attograms. Reactions are measured over time periods as long as 3 hours with high stability, showing a scatter corresponding to a fluid refractive index fluctuation of ± 4 × 10(-6) in the baseline data. Sensor arrays with a SU8 protective cladding are easy to fabricate, while oxide cladding is found to provide superior stability for measurements involving long time scales.
Optics Express 10/2010; 18(22):22867-79. · 3.59 Impact Factor
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D-X Xu, M Vachon,
A Densmore,
R Ma,
A Delâge,
S Janz,
J Lapointe,
Y Li,
G Lopinski,
D Zhang,
Q Y Liu,
P Cheben,
J H Schmid
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ABSTRACT: We report a silicon-on-insulator ring resonator biosensor array with one output port, using wavelength division multiplexing as the addressing scheme. With the use of on-chip referencing for environmental drift cancellation, simultaneous monitoring of multiplexed molecular bindings is demonstrated, with a resolution of 0.3 pg/mm(2) (40 ag of total mass) for protein concentrations over 4 orders of magnitude down to 20 pM. Reactions are measured over time periods as long as 3 h with high stability.
Optics Letters 08/2010; 35(16):2771-3. · 3.40 Impact Factor
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A Densmore, M Vachon,
D-X Xu,
S Janz,
R Ma,
Y-H Li,
G Lopinski,
A Delâge,
J Lapointe,
C C Luebbert,
Q Y Liu,
P Cheben,
J H Schmid
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ABSTRACT: We demonstrate a silicon photonic wire waveguide biosensor array chip for the simultaneous monitoring of different molecular binding reactions. The chip is compatible with automated commercial spotting tools and contains a monolithically integrated microfluidic channel for sample delivery. Each array sensor element is a 1.8-mm-long spiral waveguide folded within a 130 microm diameter spot and is incorporated in a balanced Mach-Zehnder interferometer with a near temperature independent response. The sensors are arranged in a 400 microm spacing grid pattern and are addressed through cascaded 1x2 optical power splitters using light from a single input fiber. We demonstrate the real-time monitoring of antibody-antigen reactions using complementary and mismatched immunoglobulin G receptor-analyte pairs and bovine serum albumin. The measured level of detection for each sensor element corresponds to a surface coverage of less than 0.3 pg/mm(2).
Optics Letters 12/2009; 34(23):3598-600. · 3.40 Impact Factor
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ABSTRACT: We report a SOI ring resonator biosensor array with 1 reference ring and 4 sensing rings, using WDM as the addressing scheme. On-chip referencing and temperature shift cancellation are demonstrated, and the differential signal shows a low temperature sensitivity of ~plusmn0.8 pm/degC.
Group IV Photonics, 2009. GFP '09. 6th IEEE International Conference on; 10/2009
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Adam Densmore, M Vachon,
D-X Xu,
R. Janz,
Y. -H. Ma,
G. Li,
Gregory Lopinski,
André Delâge,
J. Lapointe,
Christian Luebbert,
Qing Liu
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D-X Xu,
A Densmore,
R Ma, M Vachon,
S. Janz,
Y.-H. Li,
G Lopinski,
J. Lapointe,
A Delâge,
C. Luebbert,
Q Y Liu,
J H Schmid,
P Cheben,
Dan-Xia Xu,
Adam Densmore,
Martin Vachon,
Siegfried Janz,
Jean Lapointe,
André Delâge
[show abstract]
[hide abstract]
ABSTRACT: We report multiplexed label-free measurements of biomolecular interactions using silicon wire waveguide sensor arrays. The sensors are addressed using both wavelength division multiplexing and power broadcasting approaches. We demonstrate the real-time monitoring of antibody-antigen reactions using complementary and mismatched IgG receptor-analyte pairs and bovine serum albumin. The measured level of detection for each sensor element corresponds to a surface coverage of less than ~ 0.02% of a protein monolayer. The two addressing approaches are compared. yes yes
