Employing 532 nm Wavelength in a Laser Ultrasound Interferometer Based on Photorefractive Polymer Composites

Abstract

Laser ultrasonic (LUS) receivers based on photorefractive (PR) materials are contactless and adaptive interferometers, which are used widely for materials characterization. Here, we present a simple LUS interferometer at 532 nm operating wavelength based on organic PR polymer composites (PVK/ECZ/C60) doped with the nonlinear chromophore 4-[4-(diethylamino)-2-hydroxybenzylideneamino] benzonitrile (Dc). A picoseconds laser at 1064 nm wavelength is used to generate ultrasound pulses in aluminum plates and by using this LUS polymer interferometer, detection of these ultrasound waves is remotely performed at the surface of the specimens. The LUS sensor is used to determine the thickness of aluminum plates about 0.25 mm, 3 mm and 10 mm. We also show the potential of this polymer receiver for detection of an artificial defect in a metal sample.

Reversible holography and optical phase conjugation for image formation/correction using highly efficient organic photorefractive polymers

“…Recently, we have reported very high diffraction efficiencies at low applied electric field on PR compounds based on the dipolar arylimine chromophores H1 and H2 (Maldonado et al, 2009), see Figure 1, obtaining 87% and 75% at just E ext = 48 V/m and 32 V/m, respectively; likewise, using the chromophore Dc, from the same family, diffraction efficiencies as high as 90% and 82% were achieved at just E ext = 56 V/m and 63 V/m, respectively (Herrera-Ambriz et al, 2011). Our PR polymers based on Dc were also recently employed in a laser ultrasonic receiver (Zamiri et al, 2015) as contactless and adaptive interferometers, which are used widely for materials characterization (Davies, Edwards, Taylor, & Palmer, 1993;Zamiri et al, 2014).…”