Tunable external cavity diode laser based on integrated waveguide structures

Ion diffusion of rubidium (Rb) in potassium titanyl phosphate (KTP) creates areas of high Rb concentration. The areas of high Rb concentration have an index of refraction of as compared to the index of refraction for the KTP of The small change in the index of refraction is enough to create waveguide structures and integrated optics such as Bragg gratings in the KTP substrate. A tunable external-cavity diode laser is constructed using waveguide structures and integrated optics created by this ion diffusion. The resulting Bragg grating is used to provide optical feedback to control the operating wavelength of an external-cavity laser. Tuning is accomplished using the electro-optic properties of KTP to control the effective period of the Bragg grating. A tuning response of was measured. ©