Far-Field Subdiffraction Imaging of Semiconductors Using Nonlinear Transient Absorption Differential Microscopy
journal contributionposted on 03.02.2016 by Ning Liu, Mahendar Kumbham, Isabel Pita, Yina Guo, Paolo Bianchini, Alberto Diaspro, Syed A. M. Tofail, André Peremans, Christophe Silien
Any type of content formally published in an academic journal, usually following a peer-review process.
Label-free absorption spectroscopies are frontline techniques to reveal the spectral fingerprint, composition and environment of materials and are applicable to a wide range of samples. In an effort to improve the spatial resolution of far-field absorption microscopy, which is limited by the diffraction of light, an imaging technique based on transient absorption saturation has recently been developed. Here we report a far-field transient absorption microscopy that does not require the sample to exhibit saturable absorption to break the diffraction barrier. By alternating the wavefront of the pump beams and exploiting a nonlinearity in the transient absorption intrinsic to semiconductors, we demonstrate imaging, beyond the diffraction limit, in CdSe nanobelts. This differential technique is applied for label-free super-resolution absorption microspectroscopy.