Work

Ultra-Stable, spatially uniform monochromatic beam generation via active flux stabilization and fractional Talbot Self-Imaging

Year: 2025

Type: article

Abstract: Laser-based stable and uniform sources are necessary in various radiometry applications such as spectroradiometry, imaging, materials processing and various device characterizations. This study presents an optical system that produces a highly stable and homogeneous monochromatic beam using commercially available optical components. The stabilized laser flux fluctuates within ±40 ppm over multiple hours of operation. Beam homogenization is achieved through a microlens array-based beam integrator, expanding the beam into a uniform square profile exceeding 45×45 mm² with a spatial uniformity above 99.6%. A computational model based on Fresnel diffraction, Fourier analysis, and fractional Talbot self-imaging phenomenon has been used here to predict the beam’s irradiance distribution and behaviour. The model showed good agreement with experimental results. With an output irradiance expanded uncertainty falling as low as 0.46%, the system provides a precise and reliable platform for optical measurements calibration and device characterization.

Source: Optics & Laser Technology

DOI: 10.1016/j.optlastec.2025.113964

Authors: Salim Ferhat, Julian Gröbner

Institution: Physikalisch-Meteorologisches Observatorium Davos

Language: English

Topic: Calibration and Measurement Techniques

Subfield: Aerospace Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,230

Funder: European Partnership on Metrology