Publications de Yves Bellouard

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Ultraviolet (UV) pulses at 450 fs are a powerful tool for femtosecond laser waveguide writing in fused silica. Whereas typically sub-200 fs pulses at a high exposure dose were required, UV light efficiently creates waveguides with propagation losses below ...

Single shot SPIFI operating in the Fourier Domain is demonstrated for the first time to our knowledge. We present initial results capturing Fourier Domain single shot images with both one and two-dimensional detectors and demonstrate that the same enhanced frequency support that is characteristic of classical SPIFI translates directly into single shot SPIFI architectures as well. Linear Fourier Domain single shot SPIFI is systematically analyzed, for both types of detectors. Finally, we show that despite th

We present a novel hybrid glass-polymer micromechanical sensor by combining two femtosecond laser direct writing processes: laser illumination followed by chemical etching of glass and two-photon polymerization. This incorporation of techniques demonstrate ...

A data storage medium (2) comprising a stacked plurality of layers (9), each layer composed of a layer material selected from a group comprising at least two different dielectric materials, adjacent layers being formed of different materials, and at least ...

We demonstrate in-situ monitoring of an in-bulk fs-laser machining process of a borosilicate substrate using a co-propagating continuous wave probe at 4.46μ m provided by a mid-IR quantum cascade laser.

We demonstrate a throughput increase of third-harmonic generation microscopy imaging using arbitrary illumination patterns. A ‘camera-in-the-loop’ feedback control optimizes the hologram displayed by a spatial light modulator and two different image reconstruction methods are implemented.

The present disclosure concerns a multi-spectral image printing method. The method includes the steps of: - providing a multi-spectral image; - providing a material; - determining changes in a refractive index value of the material permitting to reproduce ...

The invention concerns a method whereby at least a predefined zone (A) of the object (2) is irradiated with a laser beam (4) capable of heating said zone sufficiently, to a temperature less than the material melting point, to provoke a change in the microstructure (for example crystallisation or recrystallisation) of said zone, said zone being heated at a temperature and for a time interval not rendering the material amorphous. The invention is applicable for example to reversible actuators and grippers.

In an optical arrangement (A) for use in an optical circuit, wherein the optical arrangement (A) comprises a substrate plate (1), wherein the substrate plate (1) is configured to receive a multitude of optical components (12.2, 12.5), the substrate plate ( ...

A novel method for the laser to fiber coupling is presented in which coarse alignment is achieved through micromachined v-grooves and mirrors in a fused silica substrate. Furthermore, fine repositioning is done in a noncontact manner by using a femtosecond ...

In laser micro-manufacturing, one of the challenges is to achieve fast scanning speed for fast fabrication of complex 3D microstructures. For microstructures with nanoscale features, it is often desirable to steer laser beams from a few microns to a few te ...

By focusing a femtosecond laser beam in the bulk of a transparent material one can locally change the physical properties of the material itself. The interaction between NIR pulses and fused silica has been extensively studied in the past, showing how vari ...

Despite remarkable progress made in recent years, producing freeform three-dimensional micro-components out of copper, silver or gold and their alloys remains an engineering challenge: current processes are either too slow to be economically viable, or pro ...

Morphing commonly refers to the smooth transition from a specific shape into another one, in which the initial and final shapes can be significantly different. In this study, we show that the concept of morphing applied to laser micro-manufacturing offers ...

Nanogratings were fabricated using a fs-laser inside more than 20 oxide glasses. Glass viscosity mostly dictates their thermal stability but deviation from this trend was observed in glasses containing large amount of Al2O3 or ZrO2. ...

Irradiation of intense ultrafast laser pulses in glasses can lead to formation of nanogratings whose periods are significantly smaller than the incident irradiation wavelength. The mechanism of the exotic phenomenon is still under hot debate. Here, we acce ...

Emergence of products that feature functional surfaces with complex geometries, such as freeform optics in consumer electronics and augmented reality and virtual reality, requires high-accuracy non-contact surface measurement. However, large discrepancies ...

Mechanical testing of materials at the microscales is challenging. It requires delicate procedures not only for producing and handling the specimen to be tested, but also for applying an accurate and controlled force. This endeavor is even more challenging ...

We present direct experimental observation of the morphological evolution during the formation of nanogratings with sub-100-nm periods with the increasing number of pulses. Theoretical simulation shows that the constructive interference of the scattering l ...

Yves Bellouard

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On the Use of UV Femtosecond Pulses to Write Waveguides in Fused Silica

Advances in single shot spatial frequency modulation imaging (SPIFI)

Combination of additive and subtractive laser 3D microprocessing in hybrid glass/polymer microsystems for chemical sensing applications

Non-volatile data storage medium and system

Dynamic Observations of Femtosecond Laser Machining in Borosilicate Using a QCL

Holographic Illumination for Fast Wide-Field Third-Harmonic Generation Imaging

Multi-spectral image priniting method

Procede de traitement par laser d'un objet en materiau a memoire de forme

Optical arrangement

Contactless Optical Packaging Concept for Laser to Fiber Coupling

Design of a miniature laser scanning head for high-bandwidth, low-amplitude beam steering

Self-organised UV Femtosecond Laser Induced Modifications in the Bulk of Fused Silica

3D metal freeform micromanufacturing

Laser-assisted morphing of complex three dimensional objects

Survival of nanogratings in high melting oxide glasses upon thermal annealing

Formation of nanogratings in a porous glass immersed in water by femtosecond laser irradiation

Lens aberration compensation in interference microscopy

A Monolithic Micro-Tensile Tester for Investigating Silicon Dioxide Polymorph Micromechanics, Fabricated and Operated Using a Femtosecond Laser

Formation of in-volume nanogratings with sub-100-nm periods in glass by femtosecond laser irradiation

High-magnification observation of flow and solidification processes of laser-melted metals in microchannels