Deep ultraviolet laser for Raman spectroscopy

NP Photonics proposes to develop an ultra-stable, compact, and highly reliable deep ultraviolet (UV) laser source for Raman spectroscopy. For this, we will draw on NP Photonics"long experience with the commercialization of single-frequency fiber lasers and amplifiers. In cooperation with the University of Arizona, we offer two technical approaches to produce the deep UV laser source. (1) High power, ultra-stable and compact single-frequency fiber laser operating at 980 nm will be developed by using NP Photonics"highly Yb-doped phosphate fibers. Two successive frequency doublers will be used to convert the high power narrow linewidth 980 nm laser to 245 nm UV laser. (2) Ultra-stable and compact single-frequency all fiber-based laser around 480 nm will be demonstrated using a distributed Bragg reflector upconversion fiber laser consisting of a short length of thulium-doped fluoride glass fiber and two Bragg fiber gratings on small-core silica fibers. The 480 nm laser is then amplified by a triple-clad thulium-doped fluoride fiber amplifier. The 240 nm UV laser will be achieved through the frequency doubling of the high power 480 nm laser. The two technical approaches for developing a compact deep UV source will be evaluated in terms of efficiency, size, robustness, and stability.