Nanotechnology is an innovative technology in the twenty-first century,is expected to revolutionize the materials technology.The field of luminescent nanomaterials is of increasing interest in recent years because this leads the way to new classes of materials with new properties in view of numerous applications,e.g.,optoelectronics,membranes,catalysis,sensors and electro-chromic devices.Light emitting rare earth doped nanomaterials have been recognized to hold tremendous potential in the area of optoelectronic and photonic applications,ranging from white LEDs,solid-state lasers,phosphors for color lamps,display panels,optical fiber telecommunications to biomedical probes.