Investigation of nanosecond laser processing of HPHT diamond (100)

Ultraviolet laser pulses were used to process grooves on HPHT diamond samples (Element Six). The morphology and size of the grooves treated with different laser processing parameters were evaluated by digital microscope (HiROX, KH-8700) and scanning electron microscope (Phenom proX). Graphitization of diamond appeared at the periphery of the irradiation area due to the laser heat conduction. The ablated groove has a V-shaped cross section due to the Gaussian distribution of the laser fluences. The influence of laser pulse energy, scanning speed, and number of scans on the width and depth of the groove has been investigated. The experiment results show that scanning speed of laser beam has little effect on the groove width. The groove width increased with the laser fluence and number of scans until reaching a saturation value. In addition, the groove depth increases with laser pulse energy and number of scans, while it decreases inversely to the scanning speed. Our work is helpful for the fabrication of diamond-based devices using ultraviolet nanosecond laser pulses.