Optical glasses were first printed on a 3D printer

Scientists managed to create glasses suitable for optical devices using a 3D printer. The authors of the technology argue that the resulting devices correspond in parameters to glasses available on the market today, obtained by the traditional method, but the technology’s potential is much higher than that of its alternatives. The results are reported in the journal Advanced Materials Technologies.

In many fields of science, technology and medicine, glasses, mirrors and lenses of optical quality are needed, that is, they introduce negligible distortions into the light of the optical range. To achieve such parameters, it is necessary that the shape of the glass surface is maintained with an accuracy not worse than the wavelength, and the distribution of the refractive index inside the body is uniform. In 3D printing, the substance is pre-melted, and since the refraction of glass depends on the cooling process, it is quite difficult to achieve the required characteristics in this case.

In the new work, scientists propose to print a part from a special paste-like material, and then heat it entirely, turning it into glass with a uniform refractive index. “Fused glass printed parts often contain textures — traces of the creation process — that remain in the bulk of the material even when the surface is polished,” said team leader Rebecca Dilla-Spears of Livermore National Laboratory in the US. “Our approach allows us to get the uniform refraction required in optics.”

In their work, the researchers used mixtures developed in the Laboratory itself for printing products with quartz or quartz-titanium glass. As a result, they were able to control the optical, thermal and mechanical properties of the final object. The paper talks about printing the first samples of relatively simple parts, but the developed method can also create much more complex products, including those with such a variable composition and such a geometric shape that are unattainable for alternative methods. In particular, it is possible to create gradient lenses – cylindrical glasses that will refract light due to the variable refractive index in the bulk of the substance, and not due to the different path lengths in the glass, as in conventional lenses. This makes polishing much easier, since it is much easier to align a flat surface t

han a curved one.