Displacement Insensitive 2D Tilt Sensor Based on End-Face Diffraction Grating Inscribed by Femtosecond Laser

A hexagonal diffraction grating has been inscribed at the end of an optical fiber using a femtosecond laser. The achieved structure has been employed to measure the 2D tilt angle being also insensitive to displacement. The achieved results suggest the potential applications of these structures to many scenarios.