Non-linear behaviours of light have been recognised as the penalty in the subject of optical science and technology. However, the authors have shown the interesting results that the non-linear property of light pulse, especially, an optical soliton, can be probed into the specific device or system to be beneficial in various cases; for instance, a soliton pulse within a nano-waveguide can form many unexpected applications. Firstly, the basic property of a soliton is analysed and described. Secondly, the use of a soliton pulse within a non-linear waveguide that can perform the various cases of benefit and application is described. The principle and application details of the systems, such as soliton background soliton in communication, sensing applications, high resolution optical lithography and spectroscopy, quantum measurement and metrology, quantum information, and finally the promising results of dark-bright soliton behaviours and related applications are proposed. The potential of applications using the proposed device and techniques for nanoscale technology is discussed herein. This is a benefit to scientists, engineers and technologists for a wide range of application in the area of optical science and technology.