High-speed measurement of rotational anisotropy nonlinear optical harmonic generation using position sensitive detection

TL;DR

This paper introduces a high-speed method for rotational anisotropy nonlinear optical harmonic generation measurements, enabling rapid and precise analysis of sample symmetries by using a stationary position sensitive detector at frequencies several thousand times faster than previous techniques.

Contribution

The authors develop a novel high-speed measurement technique that significantly improves the speed and stability of rotational anisotropy nonlinear optical harmonic generation experiments.

Findings

Successfully measured the four-fold rotational symmetry of GaAs using second harmonic generation.

Achieved measurement speeds 10^3 to 10^4 times faster than existing methods.

Demonstrated stability against laser power, beam pointing, and pulse width fluctuations.

Abstract

We present a method of performing high-speed rotational anisotropy nonlinear optical harmonic generation experiments at rotational frequencies of several hertz by projecting the harmonic light reflected at different angles from a sample onto a stationary position sensitive detector. The high rotational speed of the technique, $10^3$ to $10^4$ times larger than existing methods, permits precise measurements of the crystallographic and electronic symmetries of samples by averaging over low frequency laser power, beam pointing, and pulse width fluctuations. We demonstrate the sensitivity of our technique by resolving the bulk four-fold rotational symmetry of GaAs about its [001] axis using second harmonic generation.