A Dynamic Model for Condition Monitoring of a High-Power CO2 Industrial Laser

1999 ◽  
Vol 121 (2) ◽  
pp. 157-164 ◽  
Author(s):  
J. F. Tu ◽  
J. G. Katter ◽  
L. E. Monacelli ◽  
M. Gartner
Keyword(s):  
Co2 Laser ◽  
Laser Cooling ◽  
High Power ◽  
Power Distribution ◽  
Cooling System ◽  
Laser System ◽  
Operating Conditions ◽  
Distribution Model ◽  
Dynamic Features ◽  
Laser Systems

Industrial laser systems handle high power consumptions and may function under undesirable operating conditions if the systems are not properly maintained. It is sometimes difficult to diagnose why a laser is not functioning properly because the optical output is the result of complex interactions among many parameters such as the total gas pressure, effectiveness of the laser cooling system, operating environment, and gradual deterioration of laser components. In this paper, a dynamic power distribution model is developed to characterize the power distribution of a high-power transverse-flow DC-excited CO2 laser to account for dynamic effects such as continuously ramping up and down the laser output power and the cyclic nature of the chiller. The model contains the essential dynamic features of a CO2 laser system and yields solutions sufficiently accurate for practical diagnostic purposes.

Acoustic Microscopy for Evaluating Cracks Produced by CO2 Laser Within Thin Alumina Plates

2003 ◽  
Author(s):  
Chiaki Miyasaka ◽  
Bernhard R. Tittmann
Keyword(s):  
Crack Initiation ◽  
Co2 Laser ◽  
High Power ◽  
Laser Scanning ◽  
Process Analysis ◽  
Laser System ◽  
Acoustic Microscopy ◽  
Manufacturing Method ◽  
Post Process ◽  
Micro Cracks

The laser shaping of thin alumina ceramic plates appears to be an advantageous manufacturing method. Unfortunately, the failure rate for using this technique is high because of crack initiation during the application of a high power laser. We address the issue of crack initiation with the use of in-process and post-process analysis. This article reports our results on the evaluation of the surface and interior cracks with optical, scanning laser, scanning electron and scanning acoustic microscopy. We present images of surface and subsurface micro-cracks generated at different power levels of a high power CO2 laser system. The spatial variation of the Rayleigh wave velocity is measured by the V(z) curve technique. These preliminary data suggest that, some with improvement, the V(z) technique may detect residual stress with high spatial resolution. The obtained results may contribute to the understanding of the fracture mechanism, and can eventually provide guidance for the choice of laser parameters (e.g., power, focus, scanning rate, emitting duration, or the like) in laser shaping apparatus.

scholarly journals Comparison of Heat Transfer Theory, CFD and Experimental Results in the Design Process of High-Power Fiber Laser Cooling Plate

2021 ◽  
Vol 24 (6) ◽  
pp. 629-637
Author(s):  
Taewoo Kim ◽  
Kangin Lee ◽  
Minwan Jeong ◽  
Yeji Jeong ◽  
KwangUoong Koh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fiber Laser ◽  
Laser Cooling ◽  
High Power ◽  
Internal Flow ◽  
Operating Conditions ◽  
Transitional Flow ◽  
Cooling Plate ◽  
Transfer Theory ◽  
Heat Transfer Theory

For the stabilization of laser output power and wavelength of the high power fiber laser, the cooling plate must be properly taken into account. In this study, three analyzing methods which are heat transfer theory, CFD and experiment are used to analyze cooling plate performance by measuring pump Laser Diode(LD) temperature. Under limited operating conditions of a cooling plate, the internal flow of cooling plate is transitional flow so that the internal flow is assumed to be laminar and turbulence flow and conducted theoretical calculation. Through CFD, temperature of pump LD and characteristics of the internal flow were analyzed. By the experiment, temperature of pump LD was measured in real conditions and the performance of the cooling plate was verified. The results of this study indicate that three analyzing methods are practically useful to design the cooling plate for the high power fiber laser or similar things.

Coco II — a dual beam high power CO2 laser system

1976 ◽  
Vol 18 (1) ◽  
pp. 168-169 ◽  
Author(s):  
M.C. Richardson ◽  
N.H. Burnett ◽  
G. Enright ◽  
P. Burtyn ◽  
K. Leopold
Keyword(s):  
Co2 Laser ◽  
High Power ◽  
Laser System ◽  
Dual Beam

A simple transition-locked and polarization-forced multi-line oscillator for high-power CO2-laser systems

1979 ◽  
Vol 19 (3) ◽  
pp. 257-264 ◽  
Author(s):  
B. Gellert ◽  
J. Handke ◽  
B. Kronast
Keyword(s):  
Co2 Laser ◽  
High Power ◽  
Laser Systems

scholarly journals Direct prejudgement of hot images with detected diffraction rings in high power laser system

2018 ◽  
Vol 6 ◽  
Author(s):  
Aihua Yang ◽  
Zhan Li ◽  
Dean Liu ◽  
Jie Miao ◽  
Jianqiang Zhu
Keyword(s):  
High Power ◽  
Laser System ◽  
Front Surface ◽  
High Power Laser ◽  
Power Laser ◽  
Diffraction Ring ◽  
Main Amplifier ◽  
Laser Systems ◽  
High Power Laser System ◽  
And Cluster Analysis

A direct prejudgement strategy that takes the diffraction ring as the analysis target is put forward to predict hot images induced by defects of tens of microns in the main amplifier section of high power laser systems. Analysis of hot-image formation process shows that the hot image can be precisely calculated with the extracted intensity oscillation of the diffraction ring on the front surface of the nonlinear plate. The gradient direction matching (GDM) method is adopted to detect diffraction rings. Recognition of simulated diffraction rings shows that it is feasible to directly prejudge hot images induced by those closely spaced defects and the defects that are far apart from each other. Image compression and cluster analysis are utilized to optimize the performance of the GDM method in recognizing actually collected diffraction images. Results show that hot images induced by defects of tens of microns can be directly prejudged without redundant information.

scholarly journals The processes of vaporization in the porous structures working with the excess of liquid

2017 ◽  
Vol 21 (1 Part A) ◽  
pp. 363-373 ◽  
Author(s):  
Alexander Genbach ◽  
Nellya Jamankulova ◽  
Vukman Bakic
Keyword(s):  
Temperature Difference ◽  
High Speed ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Power ◽  
Laser System ◽  
Operating Conditions ◽  
Design Parameters ◽  
Porous Structures ◽  
The Impact

The processes of vaporization in porous structures, working with the excess of liquid are investigated. With regard to the thermal power plants new porous cooling system is proposed and investigated, in which the supply of coolant is conducted by the combined action of gravity and capillary forces. The cooling surface is made of stainless steel, brass, copper, bronze, nickel, alundum and glass, with wall thickness of (0.05-2)?10-3 m. Visualizations of the processes of vaporization were carried out using holographic interferometry with the laser system and high speed camera. The operating conditions of the experiments were: water pressures (0.01-10) MPa, the temperature difference of sub-cooling (0-20)?C, an excess of liquid (1-14) of the steam flow, the heat load (1-60)?104 W/m2, the temperature difference (1-60)?C and orientation of the system (? 0 - ? 90) degrees. Studies have revealed three areas of liquid vaporization process (transitional, developed and crisis). The impact of operating and design parameters on the integrated and thermal hydraulic characteristics was defined. The optimum (minimum) flow rate of cooling fluid and the most effective type of mesh porous structure were also defined.

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