Laser-fabricated axicons challenging the conventional optics in glass processing applications

Abstract

Laser-based fabrication can be an alternative technology to mechanical grinding and polishing processes. However, the performance of these elements in real applications still needs to be validated. In this paper, we demonstrate that the subtractive fabrication technology is able to produce high-quality axicons from fused silica, which can be efficiently used for glass processing. We comprehensively investigate axicons, fabricated by ultrashort pulsed laser ablation with subsequent CO2 laser polishing, and compare their performance with commercially available axicons. We show that laser-fabricated axicons are comparable in quality with a precision commercial axicon. Furthermore, we demonstrate the intra-volume glass modification and dicing, utilising mJ-level laser pulses. We show that the tilting operation of the laser-fabricated axicons results in the formation of directional transverse cracks, which significantly enhance the 1 mm-thick glass dicing process.

3D Manufacturing of Glass Microstructures Using Femtosecond Laser

“…While extremely complex designs achievable using additive manufacturing are out of the question [ 189 , 190 , 191 ], ablation exceeds those methods by allowing to use of glass and achieve overall size from tens of μm to mm. Optical elements, like various type lenses [ 192 , 193 , 194 ] or axicons [ 195 ], can be produced this way. In virtually all the cases additional post-processing steps are mandatory due to the necessity to smooth the surface of the structure down to optical quality (less than λ /10).…”

“…It gently melts the surface of the optical element, allowing surface tension to increase surface smoothness without compromising the overall shape ( Figure 10 ). This can be induced by heating the structure to a sufficient temperature (close to the melting of the material) [ 196 ], or by employing another laser such as CO 2 [ 192 , 193 , 194 , 195 ]. An alternative way to achieve lenses using type III laser modification is based on the idea, of inducing very fine modifications on the surface of the material.…”

“…The un-polished and polished laser-made profiles are offset to better reveal the difference between them. Reproduced from [ 195 ].…”

Multifunctional light beam control device by stimuli-responsive liquid crystal micro-grating structures

“…Axicons are a special kind of optical components with a cone-shaped phase profile, which generates a field distribution proportional to the zero-order Bessel function (non-diffracting Bessel beam). They can be used in large telescopes 27 , laser machining 28 , 29 , for medical applications 30 , 31 , or as optical tweezers 32 , 33 . Powell lenses resemble a round prism with a curved roofline and they shape a laser beam so that it stretches into a uniform line segment.…”

Dynamically taming focal fields of femtosecond lasers for fabricating microstructures

“…As a promising tool for the fabrication of optical devices and microstructures, femtosecond laser processing has been successfully employed to process various materials such as metals, semiconductors, and dielectrics [9][10][11][12][13][14][15][16] due to its characteristics of simplicity, flexibility, and high precision. In order to fabricate microstructures at the millimeter scale, an enormous number of processing points are needed; therefore, processing efficiency must be improved.…”