Curvature sensing plays an important role in structural health monitoring, damage detection, real-time shape control, modification, etc. Developing curvature sensors with large measurement ranges, high sensitivity, and linearity remains a major challenge. In this study, a curvature sensor based on flexible one-dimensional photonic crystal (1D-PC) films was proposed. The flexible 1D-PC films composed of dense chalcogenide glass and water-soluble polymer materials were fabricated by solution processing. The flexible 1D-PC film curvature sensor has a wide measurement range of 33–133 m^-1 and a maximum sensitivity of 0.26 nm/m^-1. The shift of the transmission peak varies approximately linearly with the curvature in the entire measurement range. This kind of 1D-PC film curvature sensor provides a new idea for curvature sensing and measurement.

In this Letter, we presented a flexible omnidirectional reflective film made of polymer substrates and multiple alternating layers of two chalcogenide glasses for full-angle CO2 laser protection. The structure parameters of the device were simulated for theoretical prediction of best device structure. The reflector was fabricated by alternate thermal evaporation of two chalcogenide glasses with large refractive index contrast. The reflectivity was greater than 78% at 10.6 µm. The flexible reflective film can provide an effective solution for full-angle CO2 laser protection of the moving targets, such as laser operators and mobile optical components, with potential applications for wearable laser protective clothing.