In this paper, we review the applications of the superstructured fiber Bragg grating based en/decoders. The devices are used as coding devices in the secure optical communication system and as label generator and recognizer in the optical packet switching system. The device can provide high security in the secure communication system. Besides, the single-input multiple-output device can generate and recognize a group of optical labels simultaneously. The good performance of the device promises the error-free transmission and signal processing.