An optical transmission system for an optical communications system that has an optical source, an optical modulator for modulating an optical output of the optical source, and an optical filter arranged to substantially remove one of the upper and lower sidebands of the modulated optical output of the optical source. In order to prevent ingress of water and dust, a hermetic seal is provided between the covering and components that are accessible through the covering, such as a socket or display, or components such as electrical connections. The electricity collector is provided with a main plate joined to the bundles, a rib plate bent from the main plate and extending outward of the battery pack, a mounting plate extending along the inside of the battery lid, and a connecting plate bent from of the mounting plate and extending toward a bottom surface of the battery pack. Also, a transducer with components that rotate relative to each other. A user interface is utilized to change the hierarchy, view track names, and select tracks for playback or other operations. The method also includes a sampling process for obtaining, for each optical fiber and from a sampling image, a sample injection rate which can be used for reconstructing the acquired images.