Dr. Gregory Pandraud Profile

Dr. Gregory Pandraud

at Ommatidia LIDAR

SPIE Involvement:

Editor | Author

Publications (19)

Proceedings Article | 1 April 2020 Presentation + Paper

Enhanced sensitivity of planar evanescent waveguide sensors: material and sensitivity study

Gregory Pandraud, Yu Xin, Paddy French, Olindo Isabella

Proceedings Volume 11354, 1135410 (2020) https://doi.org/10.1117/12.2555354

KEYWORDS: Waveguides, Silicon carbide, Sensors, Absorption, Silicon, Waveguide sensors, Wave sensors, Waveguide modes

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Proceedings Article | 27 April 2016 Paper

Fabrication process of Si microlenses for OCT systems

A. Jovic, G. Pandraud, K. Zinoviev, J. Rubio, E. Margallo, P. Sarro

Proceedings Volume 9888, 98880C (2016) https://doi.org/10.1117/12.2227898

KEYWORDS: Microlens, Silicon, Photoresist materials, Optical coherence tomography, Etching, Plasma etching, Image quality, Semiconducting wafers, Tomography, Infrared imaging, Photoresist processing, Surface roughness, Oxides, Dry etching, Thermal oxidation

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Proceedings Article | 21 May 2015 Paper

Low loss optomechanical cavities based on silicon oscillator

A. Borrielli, A. Pontin, F. Cataliotti, L. Marconi, F. Marin, F. Marino, G. Pandraud, G. Prodi, E. Serra, M. Bonaldi

Proceedings Volume 9517, 95171O (2015) https://doi.org/10.1117/12.2178821

KEYWORDS: Mirrors, Oscillators, Silicon, Cryogenics, Optical coatings, Computer aided design, Semiconducting wafers, Coating, Reflectivity, Microfabrication

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In an optomechanical cavity the optical and mechanical degree of freedom are strongly coupled by the radiation pressure of the light. This field of research has been gathering a lot of momentum during the last couple of years, driven by the technological advances in microfabrication and the first observation of quantum phenomena. These results open new perspectives in a wide range of applications, including high sensitivity measurements of position, acceleration, force, mass, and for fundamental research. We are working on low frequency pondero-motive light squeezing as a tool for improving the sensitivity of audio frequency measuring devices such as magnetic resonance force microscopes and gravitational-wave detectors. It is well known that experiments aiming to produce and manipulate non-classical (squeezed) light by effect of optomechanical interaction need a mechanical oscillator with low optical and mechanical losses. These technological requirements permit to maximize the force per incoming photon exerted by the cavity field on the mechanical element and to improve the element’s response to the radiation pressure force and, at the same time, to decrease the influence of the thermal bath. In this contribution we describe a class of mechanical devices for which we measured a mechanical quality factor up to 1.2 × 10⁶ and with which it was possible to build a Fabry-Perot cavity with optical finesse up to 9 × 10⁴. From our estimations, these characteristics meet the requirements for the generation of radiation squeezing and quantum correlations in the ∼ 100kHz region. Moreover our devices are characterized by high reproducibility to allow inclusion in integrated systems. We show the results of the characterization realized with a Michelson interferometer down to 4.2K and measurements in optical cavities performed at cryogenic temperature with input optical powers up to a few mW. We also report on the dynamical stability and the thermal response of the system.

Proceedings Article | 2 May 2014 Paper

Microfabrication and characterization of single-mask silicon microlens arrays for the IR spectra

Pablo N. A. Belmonte, Davies de Lima Monteiro, Rodolfo de Oliveira Costa, P. French, G. Pandraud

Proceedings Volume 9130, 91300D (2014) https://doi.org/10.1117/12.2052527

KEYWORDS: Silicon, Microlens, Microlens array, Etching, Spherical lenses, Photomasks, Infrared imaging, Microfabrication, Anisotropic etching, Semiconducting wafers

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SPIE Journal Paper | 22 November 2012

Sensing performance of plasma-enhanced chemical vapor deposition SiC-SiO2-SiC horizontal slot waveguides

Gregory Pandraud, Eduardo Margallo-Balbas, Pasqualina Sarro

JNP, Vol. 6, Issue 01, 063530, (November 2012) https://doi.org/10.1117/12.10.1117/1.JNP.6.063530

KEYWORDS: Waveguides, Silicon carbide, Refractive index, Plasma enhanced chemical vapor deposition, Biological and chemical sensing, Silicon, Sensors, Oxides, Wave propagation, Interfaces

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Proceedings Article | 9 May 2012 Paper

Surface functionalisation of TiO2 evanescent waveguide sensor for E.coli monitoring

A. Purniawan, G. Pandraud, K. Vakalopoulos, P. J. French, P. M. Sarro

Proceedings Volume 8439, 843926 (2012) https://doi.org/10.1117/12.922498

KEYWORDS: Waveguides, Sensors, Absorbance, Waveguide sensors, Atomic layer deposition, Proteins, Silicon, Silica, Plasma, Titanium dioxide

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Proceedings Article | 1 May 2012 Paper

A comparison between PECVD and ALD for the fabrication of slot-waveguide-based sensors

Grégory Pandraud, Agung Purniawan, Eduardo Margallo-Balbás, Pasqualina Sarro

Proceedings Volume 8424, 84242P (2012) https://doi.org/10.1117/12.922400

KEYWORDS: Waveguides, Silicon carbide, Plasma enhanced chemical vapor deposition, Atomic layer deposition, Sensors, Refractive index, Absorption, Silicon, Silica, Titanium dioxide

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Proceedings Article | 15 May 2010 Paper

Demonstration of PECVD SiC thermal delay lines for optical coherence tomography in the visible

Grégory Pandraud, Eduardo Margallo-Balbás, Pasqualina Sarro

Proceedings Volume 7715, 771509 (2010) https://doi.org/10.1117/12.853686

KEYWORDS: Silicon carbide, Waveguides, Optical coherence tomography, Plasma enhanced chemical vapor deposition, Birefringence, Dispersion, Refractive index, Cladding, Silica, Semiconducting wafers

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Proceedings Article | 28 February 2008 Paper

Miniature optical coherence tomography system based on silicon photonics

Eduardo Margallo-Balbás, Gregory Pandraud, Patrick French

Proceedings Volume 6847, 68470S (2008) https://doi.org/10.1117/12.766797

KEYWORDS: Silicon, Optical coherence tomography, Waveguides, Platinum, Temperature metrology, Oxides, Silicon photonics, Semiconducting wafers, Resistance, Photonic integrated circuits

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Proceedings Article | 7 February 2008 Paper

Telemetric light delivery and monitoring system for photodynamic therapy based on solid-state optodes

Eduardo Margallo-Balbás, Johan Kaptein, Henricus J. C. Sterenborg, Grégory Pandraud, Patrick French, Dominic Robinson

Proceedings Volume 6852, 68520O (2008) https://doi.org/10.1117/12.763951

KEYWORDS: Photodynamic therapy, Electronics, Light emitting diodes, Photodiodes, Solid state electronics, Tissues, Silicon, Sensors, Diodes, Data communications

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Proceedings Article | 25 January 2007 Paper

Some properties of a room temperature THz detection array

Irmantas Kašalynas, Aurèle Adam, Tjeerd Klaassen, Niels Hovenier, Grégory Pandraud, Ventzeslav Iordanov, Pasqualina Sarro

Proceedings Volume 6596, 65960J (2007) https://doi.org/10.1117/12.726404

KEYWORDS: Terahertz radiation, Sensors, Terahertz detection, Thin films, Tin, Absorption, Convolution, Gaussian beams, Imaging systems, Detector arrays

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Proceedings Article | 23 May 2005 Paper

Polarization-insensitive PECVD SiC waveguides for photonic sensing

Gregory Pandraud, Hoa Pham, Lukasz Pakula, Pasqualina Sarro, Patrick French

Proceedings Volume 5855, (2005) https://doi.org/10.1117/12.624260

KEYWORDS: Waveguides, Silicon carbide, Polarization, Plasma enhanced chemical vapor deposition, Annealing, Brain-machine interfaces, Photodetectors, Silicon, Integrated optics, Wave propagation

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Proceedings Article | 12 April 2005 Paper

Simple optical characterisation for biomimetic micromachined silicon strain-sensing structure

Dedy Wicaksono, Gregory Pandraud, Patrick French

Proceedings Volume 5852, (2005) https://doi.org/10.1117/12.621919

KEYWORDS: Silicon, Sensors, Biomimetics, Optical filtering, Fabry–Perot interferometry, Etching, Optical testing, Video, Cameras, Optical resonators

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SPIE Journal Paper | 1 July 2004

Dispersion resulting from wide passband shape in 50-GHz-spaced wavelength router

J. Gamet, Gregory Pandraud, Adrian Vonsovici

OE, Vol. 43, Issue 07, (July 2004) https://doi.org/10.1117/12.10.1117/1.1759332

KEYWORDS: Dispersion, Waveguides, Silica, Photonic integrated circuits, Multiplexers, Cladding, Multimode interference devices, Brain-machine interfaces, Etching, Integrated optics

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Proceedings Article | 15 September 1999 Paper

Bondability of processed glass wafers

Gregory Pandraud, Cheng-Qun Gui, Florent Pigeon, Paul Lambeck, Olivier Parriaux

Proceedings Volume 3825, (1999) https://doi.org/10.1117/12.364303

KEYWORDS: Semiconducting wafers, Wafer bonding, Waveguides, Glasses, Surface roughness, Ion exchange, Ions, Radium, Channel waveguides, Optical spheres

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The mechanism of direct bonding at room temperature has been attributed to the short range inter-molecular and inter-atomic attraction forces, such as Van der Waals forces. Consequently, the wafer surface smoothness becomes one of the most critical parameters in this process. High surface roughness will result in small real area of contact, and therefore yield voids in the bonding interface. Usually, the root mean square roughness (RMS) or the mean roughness (Ra) are used as parameters to evaluate the wafer bondability. It was found from experience that for a bondable wafer surface the mean roughness must be in the subnanometer range, preferentially less than 0.5 nm. When the surface roughness exceeds a critical value, the wafers will not bond at all. However RMS and Ra were found to be not sufficient for evaluating the wafer bondability. Hence one tried to relate wafer bonding to the spatial spectrum of the wafer surface profile and indeed some empirical relations that have been found. The first, who proposed a theory on the problem of the closing gaps between contacted wafers was Stengl. This gap-closing theory was then further developed by Tong and Gosele. The elastomechanics theory was used to study the balance between the decrease of surface energy due to the bonding and the increase of elastic energy due to the distortion of the wafer. They considered the worst case by assuming that both wafers have a waviness, with a wavelength (lambda) and a height amplitude h, resulting in a gap height of 2h in a head to head position. This theory is simple and can be used in practice, for studying the formation of the voids, or for constructing design rules for the bonding of deliberately structured wafers. But it is insufficient to know what is the real area of contact in the wafer interface after contact at room temperature because the wafer surface always possesses a random distribution of the surface topography. Therefore Gui developed a continuous model on the influence of the surface roughness to wafer bonding, that is based on a statistical surface roughness model Pandraud demonstrated experimentally that direct bonding between processed glass wafers is possible. This result cannot be explained by considering the RMS value of the surfaces only, because the wafers used show a RMS value larger than 1 nm. Based on the approach exposed in reference six, a rigorous analysis of wafer bonding of these processed glass wafers is presented. We will discuss the relation between the bonding process and different waveguide technologies used for implementing optical waveguides into one or both glass wafers, and give examples of optical devices benefiting from such a bonding process.

Proceedings Article | 30 August 1999 Paper

New design methodologies in (111)-oriented silicon wafers

R. Oosterbroek, J. Berenschot, A. Nijdam, Gregory Pandraud, Miko Elwenspoek, Albert van den Berg

Proceedings Volume 3874, (1999) https://doi.org/10.1117/12.361243

KEYWORDS: Etching, Semiconducting wafers, Photomasks, Silicon, Anisotropic etching, Crystals, Scanning electron microscopy, Wet etching, Deep reactive ion etching, Microsystems

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SPIE Journal Paper | 1 April 1998

New technique to produce buried channel waveguides in glass

Serge Pelissier, Florent Pigeon, B. Biasse, M. Zussy, Gregory Pandraud, Alain Mure-Ravaud

OE, Vol. 37, Issue 04, (April 1998) https://doi.org/10.1117/12.10.1117/1.601647

KEYWORDS: Channel waveguides, Semiconducting wafers, Waveguides, Wafer bonding, Ion exchange, Glasses, Wafer-level optics, Polishing, Near field, Image processing

Proceedings Article | 26 August 1996 Paper

Glass wafer direct bonding: a new technology for monomode optical integrated devices

Serge Pelissier, Gregory Pandraud, Florent Pigeon, Alain Mure-Ravaud, Jean-Pierre Meunier, B. Biasse

Proceedings Volume 2783, (1996) https://doi.org/10.1117/12.248512

KEYWORDS: Waveguides, Semiconducting wafers, Glasses, Wafer bonding, Integrated optics, Ion exchange, Wafer-level optics, Near field, Planar waveguides

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Proceedings Article | 19 August 1996 Paper

New assembly technique for deeply buried optical waveguides

Alain Mure-Ravaud, Serge Pelissier, Florent Pigeon, B. Biasse, Gregory Pandraud

Proceedings Volume 2775, (1996) https://doi.org/10.1117/12.246788

KEYWORDS: Waveguides, Semiconducting wafers, Wafer bonding, Integrated optics, Near field optics, Glasses, Ion exchange, Optical properties, Near field, Planar waveguides

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