A compact electro-optically tunable diode laser for injection seeding

Electro-optic wavelength tuning of a laser diode has been demonstrated. Wavelength control was achieved using feedback from a Bragg grating embedded in a potassium titanyl phosphate (KTP) waveguide. The novel feature of this technique is the application of a voltage across the Bragg section of the waveguide to control the reflected wavelength. Preliminary experiments on electro-optic control of a diode laser using the embedded Bragg grating resulted in a tuning range of 37 GHz, with single-frequency, CW output power of 1 mW. In these experiments, the waveguide was placed between the plates of a capacitor. Applying electrodes directly to the waveguide structure will significantly increase the tuning range and decrease the voltage required for tuning. Because the tuning mechanism does not require any moving parts, the proposed electro-optically tunable laser is compact and robust. This electro-optically controlled laser diode should be an ideal, narrow linewidth, frequency agile source for seeding high-power lidar systems