Motionless and fast measurement technique for obtaining the spectral diffraction efficiencies of a grating

TL;DR

This paper introduces a rapid, motionless method for measuring spectral diffraction efficiencies of gratings, significantly reducing measurement time and enabling dynamic and industrial applications.

Contribution

The paper presents a novel, mechanical-movement-free technique for spectral efficiency measurement, improving speed and suitability for real-time and industrial use.

Findings

Successfully tested for plane transmission gratings in 550-750 nm range

Potential to achieve millisecond measurement times

Eliminates two major mechanical movements in the measurement process

Abstract

The measurement of the spectral diffraction efficiencies of a diffraction grating is essential for improving the manufacturing technique and for assessing the grating's function in practical applications. The drawback of the currently popular measurement technique is its slow speed due to the hundreds of repetitions of two kinds of time-consuming mechanical movements during the measuring process (i.e., the rotation of the mechanical arm to capture the light beam, and the mechanical variation of the output wavelength of the grating monochromator). This limitation greatly restricts the usage of this technique in dynamic measurement. In this manuscript, we present a motionless and fast measurement technique for obtaining the spectral diffraction efficiencies of a plane grating, effectively eliminating the aforementioned two kinds of mechanical movement. Herein, the proposed solution for removing the first kind of mechanical movement is tested, and the experimental result shows that the proposed method can be successfully used to measure the plane transmission grating's spectral diffraction efficiencies in the wavelength range of 550-750 nm. The method for eliminating the second kind of mechanical movement is not verified in this manuscript; however, we think that it is very straightforward and commercially available. We estimate that the spectral measurement can be achieved on a millisecond timescale by combining the two solutions. Our motionless and fast measuring technique will find broad applications in dynamic measurement environments and mass industrial testing.