Congratulations to Ziyang Zhang for his paper published on Optics & Laser Technology
We introduce a laser processing strategy for fabricating capillaries with gradually varying diameters and cur
vature on sapphire. By dividing the capillaries into the variable power region and the fixed power region, we
have reduced the impact of energy loss caused by debris accumulation during the machining process, leading to
improved roundness. We investigate the creation of morphological deviations caused by motion errors. Utilizing
the varying impacts of scanning paths in reducing motion errors, we propose rules for developing laser scanning
paths for different capillary structures. We have successfully fabricated capillaries with diameters ranging from
50
m to 800
μ
m and lengths extending to centimeter-scale dimensions. The roughness measurement is below
100 nm, and roundness errors are less than 5
μ
m. These capillaries with diverse configurations, including
gradually varying diameters and curvature, are successfully applied to laser wakefield acceleration experiments
and accelerate electrons along the curved capillary to GeV level.