“…It should be able to generate multiwavelength lasing or tunable single wavelength lasing, in order to achieve various time delays when microwave-modulated lasings with various wavelengths are reflected at different locations of the time-delay grating. Several configurations have been used to construct a multiwavelength or single-wavelength tunable-fiber laser source, for example, strain-tuning several switchable discrete FBGs in the fiber laser's linear-cavity [5], using sampled FBGs in the cavity of the fiber-ring laser [6], or cascading several discrete FBGs in the fiber-ring laser's cavity [7]. Recently, X. P. Dong used a fiber-loop mirror (FLM) to construct a multiwavelength fiber laser [8].…”