Ultrafast Laser-Induced Damage Threshold of the Optical Materials in Near-Infrared Region

Yun Jo Lee, Purdue University


Ultrafast optics is widely used in nowadays for optical communication, tomography, remote sensing and ranging, and even fabrication methods. In order to generating the ultrafast optical signals from such applicable devices, we need to understand the threshold that the material consisting the devices can bear without any damages. Materials' Laser-Induced Damage Thresholds (LIDT) are varying with the laser's characteristics that irradiated onto the material and the materials' band gap energy. Abundant journals and papers had been published with this topic, however, it was not well studied in optical communication wavelength range. In this thesis, existing widely-accepted LIDT theory will be reviewed, and a LIDT testing setup and its results with various laser characteristics and with dierent optical materials will be proposed. Especially, LIDT of stochiometric silicon nitride (Si3N4) lm with dierent thickness has been tested. Optical materials' damaged surface by near-IR, femtosecond laser is investigated with various tools, and with comparing with the spot sizes of the laser. In future work, suggested LIDT testing setup for improving both accuracy and theoretical tness would be proposed, and LIDT study for optical waveguide aspect would be mentioned.




Qi, Purdue University.

Subject Area

Electrical engineering

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