title: Broadband terahertz ultrasonic transducer based on a laser-driven piezoelectric semiconductor superlattice.
abstract: Spectral characteristics of laser-generated acoustic waves in an InGaN/GaN superlattice structure are studied at room temperature. Acoustic vibrations in the structure are excited with a femtosecond laser pulse and detected via transmission of a delayed probe pulse. Seven acoustic modes of the superlattice are detected, with frequencies spanning a range from 0.36 to 2.5THz. Acoustic waves up to ∼2THz in frequency are not significantly attenuated within the transducer which indicates excellent interface quality of the superlattice. The findings hold promise for broadband THz acoustic spectroscopy.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. alexei.maznev@gmail.com
authors.forename: A A
authors.initials: AA
authors.lastname: Maznev
authors.forename: Kara J
authors.initials: KJ
authors.lastname: Manke
authors.forename: Kung-Hsuan
authors.initials: KH
authors.lastname: Lin
authors.forename: Keith A
authors.initials: KA
authors.lastname: Nelson
authors.forename: Chi-Kuang
authors.initials: CK
authors.lastname: Sun
authors.forename: Jen-Inn
authors.initials: JI
authors.lastname: Chyi