Feasibility Study of Laser Ablation using Long Pulsed 300W, CW Single Mode Fiber Laser

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Date

2005-06-27

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Abstract

Many applications now require micro sized holes that are difficult to produce with conventional methods. The entrance of lasers in the industry has brought about a better method for producing these holes. However the ultra-short pulse lasers that are normally used are extremely expensive and require many pulses to remove the material due to the small amount of energy they deposit. The objective of this research is to examine the feasibility of laser ablation using a 300W, CW Single Mode fiber laser which has high continuous power output for each pulse and has excellent beam quality. The results show that laser ablation occurs when a 100mm lens is used with pulse durations at 40 microseconds or below. Using one 18 microsecond pulse, a blind hole of 43.6 microns in diameter and 23.6 microns in depth with an aspect ratio of 0.54 can be created with little heat affected zone. This performance is comparable to nanosecond lasers, but with much higher hole depth per pulse. It was also found that the pulse duration must be short enough so that the ablating effect of the initial spike of an enhanced pulse is not nullified due to melting. At longer pulse durations (50 microseconds or more), raised surfaces are created instead of holes.

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Keywords

ablation, drilling, micro holes, laser

Citation

Degree

MS

Discipline

Mechanical Engineering

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