• Lu, Baozhu
• Abramchuk, Mykola
• Torchinsky, Darius H.

Abstract

<jats:p>We report on an ultralow probe-power transient grating apparatus withprobing based on a laser diode pulser, a digital delay generator, anda data acquisition card. The electronic triggering of the diode pulserpermits stroboscopic measurement of arbitrarily slow laser-induceddynamics using pulses of probe light with average power <jats:inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mo>∼<!-- ∼ --></mml:mo></mml:mrow><mml:mn>5</mml:mn><mml:mspace width="thinmathspace" /><mml:mspace width="thinmathspace" /><mml:mrow class="MJX-TeXAtom-ORD"><mml:mi mathvariant="normal">n</mml:mi><mml:mi mathvariant="normal">W</mml:mi></mml:mrow></mml:math></jats:inline-formula>, significantly lower than what iscurrently used by continuous wave measurement. The proposed methodalso allows for flexibility in selection of the probe wavelengthlimited only by availability of low threshold current laser diodes.Examples of impulsive stimulated thermal scattering measurements arepresented on liquid isopropanol, single crystal solid <jats:inline-formula><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow class="MJX-TeXAtom-ORD"><mml:msub><mml:mrow class="MJX-TeXAtom-ORD"><mml:mi mathvariant="normal">C</mml:mi><mml:mi mathvariant="normal">r</mml:mi><mml:mi mathvariant="normal">C</mml:mi><mml:mi mathvariant="normal">l</mml:mi></mml:mrow><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math></jats:inline-formula>, and a thin film of Cu vapordeposited on a Si substrate, demonstrating the flexibility of thetechnique.</jats:p>

Topics

• single crystal
• thin film
• optical rotatory dispersion