Frequency-Agile Monolithic Micro-Laser with Ultra-Narrow Linewidth

"A method for generating a high power, continuous wave (cw) monolithic micro-laser with rapidly tunable, narrow linewidth output is proposed. The concept employs a semiconductor laser coupled to an electro-optically controlled Bragg waveguide in PotassiumTitanyl Phosphate (KTP) providing single frequency output. Frequency tuning is achieved by applying a voltage across the waveguide, thereby changing its index of refraction. The targeted tuning range is 30 GHz in 1 ms by applying 18 volts across thewaveguide. The output of the laser will be amplified to 1 Watt using a commercially available Yb-doped fiber amplifier. The combined system will provide a high power, rapidly tunable, single frequency output in a robust, monolithic package ideal fortracking fast moving objects in the atmosphere.KTP is an ideal medium for this application because of its high electro-optic figure of merit (~36 pm/V), high threshold for optical damage (~1 GW/cm2), low susceptibility to photo-refractive damage, and the ability to form low loss (0.5 dB/cm) waveguidesusing standard ion exchange techniques. KTP is transparent from 350 nm to 4500 nm, so the device will work for a wide variety of wavelengths ranges. The proposed monolithic laser will provide rapid tuning over a broad frequency range at high power making it ideal for laser tracking and spectroscopy."