Fig. 1. Scheme for generation of LSPR of metal nanocrystal excited by electromagnetic wave

Fig. 2. Spectral range of LSPR resonant peak along with shape and material change of precious metal nanocrystals[9]

Fig. 3. Morphologies of various metal nanocrystals synthesized by solution-based chemical reaction. (a) Gold nanospheres[38]; (b) gold nanorods[39]; (c) gold nanocages[40]; (d) gold nanotriangles[41]; (e) gold nanostars[42]; (f) gold nanorices[43]; (g) gold nanocapsules[44]

Fig. 4. Morphologies and SERS performances of metal nanocrystals hybridized optical fibers prepared based on PCF sucking. (a) Morphology of silver nanocrystals hybridized photonic crystal fiber prepared by sucking and drying method and its SERS performance in detection of Rhodamine B molecules[15]; (b) morphology of silver nanocrystals hybridized photonic crystal fiber prepared by sucking and chemical bonding method and its SERS performance in detection of Rhodamine 6G molecules[16]

Fig. 5. SEM image of end of optical fiber with transferred metal dots array[60]

Fig. 6. Morphologies of metal nanocrystals hybridized optical fibers fabricated by electron beam lithography (EBL) and focused ion beam (FIB) etching. (a) SEM image and transmission spectrum of optical fiber with Au nanodot array prepared by EBL on facet[61]; (b) SEM image and transmission spectrum of optical fiber with Au nanohole array prepared by FIB on facet[26]

Fig. 7. Application of metal nanocrystals hybridized optical fibers in random fiber laser. (a)Structure, pumping approach, and laser performance of PMMA optical fiber co-doped with Ag nanocrystals and Rhodamine 6G[20]; (b) microscope photos, pumping approach, and laser performance of polymer optical fiber co-doped with Au nanocrystals and PM597 dye[21]; (c)structure and laser performance of F8BT optical fiber co-doped with Au nanocrystals[69]