title: Photoacoustic absorption spectrometer for highly transparent dielectrics with parts-per-million sensitivity.
abstract: A sensitive photoacoustic absorption spectrometer for highly transparent solids has been built and tested. As the light source an optical parametrical oscillator pumped by a nanosecond pulse laser with 10 Hz repetition rate is employed, covering the complete wavelength range from 407 to 2600 nm. A second-harmonic-generation unit extends the range of accessible wavelengths down to 212 nm. A lead-zirconate-titanate piezo transducer, directly coupled to the sample, detects the photoacoustically generated sound waves. Absorption spectra of lithium triborate, lithium niobate, and alpha barium borate crystals with absorption coefficients down to 10(-5) cm(-1) are presented.
authors: Fraunhofer Institute for Physical Measurement Techniques IPM, Heidenhofstrasse 8, 79110 Freiburg, Germany. niklas.waasem@ipm.fraunhofer.de
authors: Niklas
authors: N
authors: Waasem
authors: Stephan
authors: S
authors: Fieberg
authors: Janosch
authors: J
authors: Hauser
authors: Gregory
authors: G
authors: Gomes
authors: Daniel
authors: D
authors: Haertle
authors: Frank
authors: F
authors: Kühnemann
authors: Karsten
authors: K
authors: Buse