Single laser pulse generates dual photoacoustic signals for differential contrast photoacoustic imaging.

ABSTRACT: Photoacoustic sensing and imaging techniques have been studied widely to explore optical absorption contrast based on nanosecond laser illumination. In this paper, we report a long laser pulse induced dual photoacoustic (LDPA) nonlinear effect, which originates from unsatisfied stress and thermal confinements. Being different from conventional short laser pulse illumination, the proposed method utilizes a long square-profile laser pulse to induce dual photoacoustic signals. Without satisfying the stress confinement, the dual photoacoustic signals are generated following the positive and negative edges of the long laser pulse. More interestingly, the first expansion-induced photoacoustic signal exhibits positive waveform due to the initial sharp rising of temperature. On the contrary, the s

SUBMITTER: Gao F 

PROVIDER: S-EPMC5429673 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature