The temperature distribution due to a rotating or dithering Gaussian laser beam on a finite body is obtained numerically. The authors apply various techniques to solve the nonhomogeneous heat equation in different spatial dimensions. The authors’ approach includes the Crank-Nicolson method, the Fast Fourier Transform (FFT) method and the commercial software COMSOL. It is found that the maximum ...

Transient thermal field in laser surface hardening treatment of medium carbon steel was analyzed by employing both three-dimensional analytical model and finite element model. In finite element model the laser beam was considered as a moving plane heat flux to establish the temperature rise distribution in the work-piece, while in analytical model laser beam was considered as an internal heat s...

We study the maximum temperature rise induced by a rotating or dithering Gaussian laser beam on a semi-infinite body. An analytical solution is obtained by solving the transient three-dimensional heat equation in a semi-infinite domain with insulating surface. The effect of rotating or dithering frequency on maximum temperature rise is quantitatively investigated for stainless steel and carbon ...

Directional dithering of a laser beam potentially limits the detection accuracy of a laser triangulation displacement probe. A theoretical analysis indicates that the measurement accuracy will linearly decrease as the laser dithering angle increases. To suppress laser dithering, a laser triangulation displacement probe with laser beam pointing control, which consists of a collimated red laser, ...

Directional dithering of a laser beam potentially limits the detection accuracy of a laser triangulation displacement probe. A theoretical analysis indicates that the measurement accuracy will linearly decrease as the laser dithering angle increases. To suppress laser dithering, a scheme for reduction of the influence of laser beam directional dithering in a laser triangulation displacement pro...

We demonstrate the coherent combining of three beams with a phase-locking controller using VLSI multidithering technique. Three …ber-coupled phase shifters are used to compensate phase distortions in the beam propagation path. The highest dither frequency in our system is 70MHz. The achieved closed-loop compensation bandwidth of three beamlets is up to 100KHz. Keywords: coherent beam combining,...

We study the maximum temperature rise induced by a rotating or dithering Gaussian laser beam on a two-layer body. First, we derive semi-analytical solutions by solving the transient threedimensional heat equation in a semi-infinite domain with insulating surface. Second, we provide numerical solutions for a two-layer structure in a finite domain. Our results show that the maximum temperature ri...

Color Halftoning, Dithering. This report introduces the problem of dithering in a simplex, and suggests a few possible solutions. In general, dithering can be viewed as a method for describing color images using a combination of allowed output colors. Usually the convex hull of the set of allowed output colors is a cube in the color space. However, there are cases when the convex hull is a simp...

The Quantization Theorem I (QT I) implies that the likelihood function can be reconstructed from quantized sensor observations, given that appropriate dithering noise is added before quantization. We present constructive algorithms to generate such dithering noise. The application to maximum likelihood estimation (mle) is studied in particular. In short, dithering has the same role for amplitud...