Optimization of pencil beam f-theta lens for high-accuracy metrology

Peng, Chuanqian; He, Yumei; Wang, Jie

doi:10.1117/1.oe.57.1.015101

Cited by 4 publications

(2 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A 5-mm diameter collimated laser beam passes through a Focal-piShaper (πShaper, Berlin, Germany), gets into a scanning head and deviates according to the signal from a scanning program from a PC by a system of reflective mirrors. Further it passes through an focal (f -Theta) lens [42,43] and impacts the powder layer on a substrate made in the form of a disc. A charge-coupled device (CCD) camera LaserCam-HR (Coherent, Palo Alto, CA, USA) controls power distribution in a laser beam.…”

Section: Methodsmentioning

confidence: 99%

Power Density Distribution for Laser Additive Manufacturing (SLM): Potential, Fundamentals and Advanced Applications

et al. 2018

View full text Add to dashboard Cite

Problems with the laser additive manufacturing of metal parts related to its low efficiency are known to hamper its development and application. The method of selective laser melting of metallic powders can be improved by the installation of an additional laser beam modulator. This allows one to control the power density distribution optically in the laser beam, which can influence the character of heat and mass transfer in a molten pool during processing. The modulator contributes alternative modes of laser beam: Gaussian, flat top (top hat), and donut (bagel). The study of its influence includes a mathematical description and theoretical characterization of the modes, high-speed video monitoring and optical diagnostics, characterization of processing and the physical phenomena of selective laser melting, geometric characterization of single tracks, optical microscopy, and a discussion of the obtained dependences of the main selective laser melting (SLM) parameters and the field of its optimization. The single tracks were produced using the advanced technique of porosity lowering. The parameters of the obtained samples are presented in the form of 3D graphs. The further outlook and advanced applications are discussed.

show abstract

Section: Methodsmentioning

confidence: 99%

Power Density Distribution for Laser Additive Manufacturing (SLM): Potential, Fundamentals and Advanced Applications

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Based on the optimization design method of single ray tracing, 11 an optimization scheme of RPs to meet the requirements of a normal tracing angle measurement system is proposed in this paper.…”

Section: Introductionmentioning

confidence: 99%

Research on achromatic Risley prism in normal tracing angle measurement system

et al. 2022

Self Cite

View full text Add to dashboard Cite

.The normal tracing angle measurement system based on Risley prisms can eliminate the influence of aberrations other than the dispersion of Risley prisms on the angle measurement accuracy. Although the traditional dispersion optimization method based on the extreme point can make the beam directions of different wavelengths more consistent after passing through the Risley prisms, the light intensity distribution that deviates from the extreme point wavelength causes the spot centroid to deviate from the target position, thus introducing the angle measurement error. In this paper, we propose a highly symmetry-glued achromatic Risley prisms optimization method for the needs of a normal tracing angle measurement system. Our method not only realizes the beam direction as closely as possible after the deflection of the Risley prisms but also compensates for the centroid error caused by the beam deviating from the central wavelength. ZEMAX simulation shows that, in the normal tracing angle measurement system, within the angle measurement range of ±700 ″ and the light source wavelength range of 600 to 700 nm, the angle measurement error introduced by the dispersion of the optimized Risley prisms is not >0.01 ″ .

show abstract