Open AccessHigh-efficient photoacoustic generation with an ultrathin metallic multilayer broadband absorber
Author(s) -
Chunqi Zheng,
Huanzheng Zhu,
Zhifei Xu,
Ravindra Kumar Sinha,
Qiang Li,
Pintu Ghosh
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.420138
Subject(s) - materials science , optoelectronics , absorbance , optics , absorption (acoustics) , laser , nanomaterials , wavelength , layer (electronics) , thin film , nanotechnology , composite material , physics
Metal nanomaterials have been widely used to generate photoacoustic (PA) signals because of their high optical absorption characteristics. However, the PA conversion efficiency of metal nanomaterials is limited by the single-wavelength absorption at the resonant peak. To mitigate this issue, a three-layer ultrathin film containing a thin PDMS layer sandwiched between two ultrathin chromium films is proposed. This kind of film structure can attain high optical absorbance (>80%) through the visible light range (450-850 nm). The optical absorption characteristics can be easily modulated by varying the thickness of the PDMS layer. Under the same excitation condition, the PA signal generated by this film structure is twice that of an only Cr film and three times that of an only Au film. This film structure is easily fabricated and can operate with lasers having different central wavelengths or even white light sources, leading to its applications in many fields, including photoacoustic communications and audio transducers.