Fiber Bragg Gratings have many applications in optical communication, laser technique and sensing systems. The FBGs are widely used like in-fiber mirrors or optical filters with narrow band optical spectrum. FBGs can be used like a sensitive element for strain and temperature measuring. The Wavelength Locker FBGs are used as external reflectors for laser diodes. It is easy to stabilize wavelength generation of pump semiconductor lasers and single frequency lasers by using such FBGs. Low reflection gratings with FWHM 0.3 ÷ 0.8 nm and reflectivity 2 ÷ 5 % are ideal for pump power lasers stabilization. Close to semiconductor laser crystals FBGs with FWHM around 0.1 nm and reflection 10 ÷ 20% are used for creation single frequency sources. We are presented line of the WL FBG with vary accurate wavelength positions up to ± 0.02 nm. The transmission spectrum of Wavelength Locked FBG for laser diode power and wavelength stabilize is presented in the graph.