Glass ablation and cutting with a femtosecond Bessel beam

Glass drilling and cutting is crucial for optics, consumer electronics, and Micro-Electro-Mechanical System (MEMS) devices. Speed and reproducibility are issues common to traditional glass cutting methods. We use a femtosecond laser to efficiently and accurately cut interior shapes in glass. Unlike a traditional Gaussian beam, which has a shallow focal range and cannot penetrate deep into materials, Bessel beams have a much longer focal range, up to millimeters. With a Bessel beam, we can cut straight through without the need for mechanical cleaving or moving the sample through the focus, improving reproducibility and speed. The cut surfaces are analyzed with optical microscopy, atomic force microscopy, and scanning electron microscopy to observe any structural/morphological changes to the materials near the laser affected regions. Our 260fs laser operates at 10kHz, with 1030nm central wavelength, depositing 1.4W on target. An axicon generates the Bessel beam with a FWHM central spot size of 6±1µm and a fluence of up to 41Jcm-2. Our study has the potential to open new technological pathways for integrated electronic and photonic platforms.