All-Electronic Phase-Resolved THz Microscopy Using the Self-Mixing Effect in a Semiconductor Laser
All-Electronic Phase-Resolved THz Microscopy Using the Self-Mixing Effect in a Semiconductor Laser
复制标题
DOI：
10.1021/acsphotonics.0c01908
复制
发表时间：
2021-03
期刊：
影响因子：
7
通讯作者：
P. Rubino;J. Keeley;N. Sulollari;A. Burnett;A. Valavanis;Imon Kundu;M. Rosamond;Lianhe H. Li
中科院分区：
文献类型：
--
作者：
P. Rubino;J. Keeley;N. Sulollari;A. Burnett;A. Valavanis;Imon Kundu;M. Rosamond;Lianhe H. Li
报道了使用太赫兹量子级联激光器的全电子相干散射型扫描近场显微镜(S-SNOM)。通过利用这些激光器中的相干自混合效应，结合激光的电子频率调谐，我们展示了散射场的幅度和相位的深亚波长分辨率的空间映射。我们将我们的技术应用于声子共振晶体的相干显微镜。提取的振幅和相位参数与金属和非共振介质材料相比显示出明显的对比，并与用有限偶极子模型计算的结果非常一致。我们的技术为在太赫兹频率下的固态系统和光电纳米器件的介电函数的快速纳米分辨率映射铺平了道路。
We report all-electronic coherent scattering-type scanning near-field microscopy (s-SNOM) using a terahertz-frequency quantum cascade laser. By exploiting the coherent self-mixing effect in these lasers, in conjunction with electronic frequency tuning of the laser, we demonstrate spatial mapping of both the amplitude and the phase of the scattered field with deeply subwavelength resolution. We apply our technique for coherent microscopy of a phonon-resonant crystal. The extracted amplitude and phase parameters reveal clear contrast when compared to both metallic and nonresonant dielectric materials and show excellent agreement with those calculated using a finite-dipole model of the near-field interaction between the s-SNOM tip and the resonant sample in the Reststrahlen band. Our technique paves the way for fast nanoscale-resolved mapping of the dielectric function of solid state systems and optoelectronic nanodevices at terahertz frequencies.