Detection of ultrasonic motion of a scattering surface by two-wave mixing in a photorefractive GaAs crystal

Blouin, Alain; Monchalin, Jean‐Pierre

doi:10.1063/1.112153

Cited by 138 publications

(75 citation statements)

References 5 publications

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“…In any cases, a laser beam is sent on the surface to be probed and the ultrasound wave travelling to the surface will perturb the phase of the laser probe beam. These variations can be measured through a passive interferometer, like the confocal Fabry Perot (FP) [2] , or through adaptive interferometers based on the two-wave mixing (TWM) in photorefractive crystals [8] .…”

Section: Introductionmentioning

confidence: 99%

Non destructive inspection of aerospace composites by a fiber-coupled laser ultrasonics system

Vandenrijt

Languy

Thizy

et al. 2017

Fifth International Conference on Optical and Photonics Engineering

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Laser ultrasonics is a technique currently studied for nondestructive inspection of aerospace composite structures based on carbon fibers. It combines a pulsed laser impacting the surface generates an ultrasound inside the material, through the nondestructive thermoelastic effect. Second a detection interferometer probes the impacted point in order to measure the displacement of the surface resulting from the emitted ultrasound wave and the echo coming back from the different interfaces of the structure. Laser ultrasonics is of interest for inspecting complex shaped composites. We have studied the possibility of using frequency doubled YAG laser for the generation and which is fiber-coupled, together with a fibercoupled interferometric probe using a YAG laser in the NIR. Our final system is a lightweight probe attached to a robot arm and which is able to scan complex shapes. The performances of the system are compared for different wavelengths of generations. Also we have studied some experimental parameters of interest such as tolerance to angle and focus distance, and different geometries of generation beams. We show some examples of inspection of reference parts with known defects. In particular C-scans of curved composites structures are presented.

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Section: Introductionmentioning

confidence: 99%

Non destructive inspection of aerospace composites by a fiber-coupled laser ultrasonics system

Vandenrijt

Languy

Thizy

et al. 2017

Fifth International Conference on Optical and Photonics Engineering

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“…Adaptive optical interferometry [3][4][5][6][7] uses an adaptive beam mixer, for example photorefractive materials, instead of a beamsplitter to generate interference between a local oscillator and signal beam. By automatically compensating time and spatial perturbations in the input fields, a steady quadrature condition can be maintained in an adaptive interferometer, which enables pure phase-sensitive detection, such as ultrasound detection [8 -12].…”

Section: Introductionmentioning

confidence: 99%

Adaptive interferometry of protein on a BioCD

et al. 2007

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Adaptive spinning-disk interferometry is capable of measuring surface profiles of a thin biolayer with subnanometer longitudinal resolution. High-speed phase modulation in the signal beam arises from the moving surface height profile on the spinning disk and is detected as a homodyne signal via dynamic two-wave mixing. A photorefractive quantum-well device performs as an adaptive mixer that compensates disk wobble and vibration while it phase-locks the signal and reference waves in the phase quadrature condition (͞2 relative phase between the signal and local oscillator). We performed biosensing of immobilized monolayers of antibodies on the disk in both transmission and reflection detection modes. Single-and dual-analyte adaptive spinning-disk immunoassays were demonstrated with good specificity and without observable cross-reactivity. Reflection-mode detection enhances the biosensing sensitivity to one-twentieth of a protein monolayer, creates a topographic map of the protein layer, and can differentiate monolayers of different species by their effective optical thicknesses.

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“…Compared to other wide field of view interferometers, like the FP or the TWM [4], it suffers from its slow turn-on time. This turn-on time, which is linked to the conjugate beam build-up time, is adversely affected by the low light level collected from the scattering surface.…”

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confidence: 99%

“…This can be done by using a Fabry-Perot (FP) [2] which is a self-reference interferometer and means that the reference beam is generated by the signal beam. It can also be done by using two-wave mixing (TWM) in a photorefractive crystal [3,4]. In this case, the reference beam is created by the diffraction of a plane wave pump beam by the hologram written by both pump and signal beams.…”

mentioning

confidence: 99%

Heterodyne Detection of Ultrasound from Rough Surfaces Using a Double Phase Conjugate Mirror

Delaye

Blouin

Drolet

et al. 1996

Review of Progress in Quantitative Nondestructive Evaluation

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Ultrasonic excitation of a solid sample (optically opaque) can be detected by directing a laser beam at one of its surfaces. Surface motion causes a transient phase shift upon the scattered light, which has to be demodulated into an intensity variation prior to its detection by a photodetector. Classical reference beam interferometry (homodyne or heterodyne) is a well-known technique for performing this demodulation. It is characterized by a broad detection bandwidth, but is, following the antenna theorem [1], essentially limited to the detection of one speckle, when used on rough surfaces. In order to circumvent this limitation (i.e., in order to increase the etendue of the interferometer), two different approaches for adapting the signal and reference wavefronts have been considered. The first approach proceeds by creating a reference beam that matched the wavefront of the signal beam. This can be done by using a Fabry-Perot (FP) [2] which is a self-reference interferometer and means that the reference beam is generated by the signal beam. It can also be done by using two-wave mixing (TWM) in a photorefractive crystal [3,4]. In this case, the reference beam is created by the diffraction of a plane wave pump beam by the hologram written by both pump and signal beams. Alternatively the signal beam wavefront can be adapted to the reference wavefront, which requires, since the reference beam can usually be approximated by a plane wave, the transformation of the speckled beam to a beam with a plane wavefront. Devices using externally pumped [5] or self-pumped phase conjugate mirrors (SPCM) [6] have been reported. These schemes require two reflections on the sample surface which strongly limit the sensitivity when the surface is absorbing. The Double Phase Conjugate Mirror (DPCM) is a speckle to plane wavefront converter when one of the two beams creating the mirror is a plane wave [7]. A DPCM was previously used in a heterodyne scheme to produce a wide-field of view interferometer [8] for remote sensing. It has also been used in an homodyne interferometer for ultrasound detection [9].

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Detection of ultrasonic motion of a scattering surface by two-wave mixing in a photorefractive GaAs crystal

Cited by 138 publications

References 5 publications

Non destructive inspection of aerospace composites by a fiber-coupled laser ultrasonics system

Non destructive inspection of aerospace composites by a fiber-coupled laser ultrasonics system

Adaptive interferometry of protein on a BioCD

Heterodyne Detection of Ultrasound from Rough Surfaces Using a Double Phase Conjugate Mirror

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