Printing Glass

This article that inspires this cover explains how three-dimensional (3D) printing is now being applied to create tiny optical components made from strong glass and ceramic materials. Traditionally, these optics, like lenses and waveguides, were made by carving or shaping solid blocks, which limited the shapes and complexity that could be achieved. With 3D printing, designers can build structures layer by layer and control their shape down to the scale of hundreds or even tens of nanometers, allowing for new designs that can better manipulate light.

A key topic covered is a specific 3D printing technique called two-photon lithography (TPL). TPL allows for high precision by using focused laser pulses to shape materials in three dimensions, making it possible to print with glass and ceramics that are more durable and stable compared to plastics. The article discusses how scientists customize the liquids, called photoresins, used in the printing process so they contain the right mix of ingredients to turn into glass or ceramic after printing and heating. It also addresses the technical challenges, such as avoiding defects and controlling the physical and optical properties at very small scales, that must be overcome for these components to meet the requirements of today's micro-optics industry.

The article also explores how multiple glass and ceramic materials can be combined in one printed object, making it possible to create complex devices with different properties in different parts. This capability is especially relevant to modern technology, from fiber optic communications and imaging devices to quantum optics and electronics. Finally, the authors encourage further collaboration to improve both the materials and the precision of 3D printing, aiming for future micro-optical systems that are more reliable and versatile in harsh environments like those found in the semiconductor or photonics industry.