雷射光變形設計及雷射功率穩定性分析

Laser light mask shape design and Analysis of laser power stability

邱奕霖(Yi-Lin Chiu)

指導教授 ： 湯華興 ； 嚴孝全

國立臺北科技大學/機電學院/製造科技研究所/碩士(2011年)

摘要

本文目的為設計並製作本校自主研發之快速原型機之雷射掃描系統的導光系統，並使雷射功率有良好的穩定性，再運用遮罩改變雷射光束形狀，以期得到均勻的雷射光束能量。
雷射分別以空氣及水冷卻，並使用雷射功率計進行雷射功率量測。在比較氣冷、水冷雷射機的穩定度後，再量測閉迴路控制功率之雷射穩定度。最後發現以水冷方式配合功率回授控制之組合可以得到最穩定的系統。
以CO2雷射進行掃描時，能量呈現高斯分佈。欲得到均勻之雷射掃描，本研究將雷射束徑放大，並利用遮罩改變雷射光束形狀，最後將修正後之光束聚焦於工作面上。由於掃描路徑上的材料皆吸收相同能量，其路徑底部呈平坦狀態，而非高斯分佈。

關鍵字

雷射光束變形 ； 雷射功率穩定

並列摘要

The purpose of current study is to design a laser scanning system for a homemade rapid prototyping apparatus, to stabilize laser power, and to obtain a uniform energy of the laser beam by using a mask to modify the shape of laser beam.
Laser was cooled with air and water, respectively, and laser power was measured by a power meter. After comparing the laser power stability obtained from those cooling system. The stability was measured with close-loop power control. The optimum stability was achieved by water cooling with close- loop power control.
When scanning with a CO2 laser, the energy distribution is Gaussian function. To homogenize laser scanning, we expanded the laser beam, and modified the distribution by a mask. Eventually, the modified laser beam was focused on a working plane. Because all materials along the scanning path absorbed the same amount of energy, the bottom of the scanning path was flat rather than a Gaussian distribution.

並列關鍵字

laser light mask shape ； laser power stability

參考文獻

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