Ultra-thin glass as a substrate for flexible photonics

Flexible photonics is an emerging field in optical materials for several frontier applications. New ultra-thin glasses with thicknesses ranging from tens to hundreds of microns are potential candidates as substrates for flexible photonics applications. The improvement in mechanical performance, specifically retained strength, for such glasses is achieved by composition design and ion exchange post-processing. The main physical effects to be considered are the introduction of residual stress profiles and refractive index modifications. Both aspects may interfere with flexible photonics application of these glass substrates. The physics of stress buildup and relaxation are discussed, as well as the impact on refractive index. The discussion also considers promising glass compositions widely used in consumer electronics applications.