Complete characterization of beam deflection based on double weak value amplification system

TL;DR

This paper presents a novel method for simultaneously measuring two-dimensional beam deflections using a double weak value amplification system, achieving high precision in yaw and pitch angle detection.

Contribution

The work introduces a combined theoretical and experimental approach for complete 2D beam deflection characterization using Hermite-Gaussian modes and high-order-mode homodyne detection.

Findings

Minimum measurable yaw angle: 83 prad

Minimum measurable pitch angle: 89 prad

Displacement sensitivity around 0.8 pm

Abstract

The precise measurement of spatial attitude parameters is critical for applications in inertial navigation, industrial monitoring, instrument calibration, quantum metrology, etc. In this work, we theoretically investigate and experimentally realize the simultaneous measurement of the yaw and pitch angles using a Hermite-Gaussian-postselected double weak value system integrated with two sets of high-order-mode balanced homodyne detections, thereby achieving a complete characterization of the beam deflection. Signals of the yaw and pitch angles that are involved in TEM$_{10}$ and TEM$_{01}$ modes output from two dark ports of the system can be measured independently. As a result, the obtained minimum measurable yaw and pitch angles of beam deflection are 83 prad and 89 prad, respectively. Meanwhile, the corresponding displacements are 0.79 pm and 0.85 pm, respectively. This work expands the beam deflection measurement to two dimensions, which provides a new insight for future high-precision multi-parameter spatial precise detection.