An inflatable vehicle occupant protection device has a vent panel defining a first vent opening for enabling flow of inflation fluid out of the device. In further embodiments, a multi-layer dielectric structure is formed by forming a first dielectric layer on a substrate according to an ALD process and forming a second dielectric layer directly on the first dielectric layer according to a CVD process. This increase occurs along either a transition or contact portion of the ground terminal. As strain is applied to the fiber, the optical spectrum center wavelength reflected by the Bragg grating shifts in wavelength. A displaying unit outputs the program information according to a predetermined displaying method.