Fast reflective optic-based rotational anisotropy nonlinear harmonic generation spectrometer
Abstract
We present a novel Rotational Anisotropy Nonlinear Harmonic Generation (RA-NHG) apparatus based primarily upon reflective optics. The data acquisition scheme used here allow for fast accumulation of RA-NHG traces, mitigating low frequency noise from laser drift, while permitting real-time adjustment of acquired signals with significantly more data points per unit angle rotation of the optics than other RA-NHG setups. We discuss the design and construction of the optical and electronic components of the device and present example data taken on a GaAs test sample at a variety of wavelengths. The RA-second harmonic generation data for this sample show the expected four-fold rotational symmetry across a broad range of wavelengths, while those for RA-third harmonic generation exhibit evidence of cascaded nonlinear processes possible in acentric crystal structures.
- Publication:
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Review of Scientific Instruments
- Pub Date:
- May 2019
- DOI:
- 10.1063/1.5080965
- arXiv:
- arXiv:1811.01862
- Bibcode:
- 2019RScI...90e3102L
- Keywords:
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- Physics - Instrumentation and Detectors;
- Physics - Optics
- E-Print:
- doi:10.1063/1.5080965