|
High-Energy Short-Pulse Fiber Amplifier at Eye-Safe Wavelengths
Navy SBIR 2008.1 - Topic N08-050 NAVSEA - Mr. Dean Putnam - [email protected] Opens: December 10, 2007 - Closes: January 9, 2008 N08-050 TITLE: High-Energy Short-Pulse Fiber Amplifier at Eye-Safe Wavelengths TECHNOLOGY AREAS: Electronics, Weapons ACQUISITION PROGRAM: PMS 405 Ultra Short Pulse Laser Development. ACAT leve N/A The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), which controls the export and import of defense-related material and services. Offerors must disclose any proposed use of foreign nationals, their country of origin, and what tasks each would accomplish in the statement of work in accordance with section 3.5.b.(7) of the solicitation. OBJECTIVE: Develop and demonstrate an efficient, all-fiber amplifier capable of amplifying pulses at high repetition rates to the millijoule energy level with high average power and compressible to <500 fs duration. The fiber amplifier output should be single spatial mode at eye-safe wavelengths. The fiber should be bendable to a reasonably tight diameter to enable packaging in a compact form DESCRIPTION: Ultra-short pulse (USP) lasers offer a variety of potential applications of interest to the Navy in the fields of sensing, diagnostics and distance interrogation as well as with weapons potential. At the pulse energy levels of interest, current state of the art high-power USP laser-amplifier systems are bulky and offer only low efficiency, greatly restricting the deployment of USP lasers for practical applications. Due to their compactness, suitability for direct diode laser pumping, high efficiency and scalability, the Navy is interested in the development of high peak and average power, high-energy all-fiber amplifiers suitable for chirped-pulse amplification systems at eye-safe wavelengths. High-energy lasers at eye-safe wavelengths present much lower ocular hazards to the military personnel than lasers emitting at other wavelengths. Such systems would enable numerous applications and allow for easier integration into existing sea and air based platforms. Scaling the pulse energies from chirped-pulse fiber amplifiers to the millijoule level at high average power has been limited by the nonlinear effects in fiber that are detrimental to the amplified pulse quality. These non-linearities, limit the minimum pulse durations achievable by pulse compression following the amplification. Large mode-area (LMA) fibers enable the reduction of nonlinear effects however at the expense of pure single mode operation. As a result, mode field areas in LMA fiber amplifiers have been limited to a few 100 �m2. In order to scale up the pulse energy from fiber amplifiers to useful levels for applications of interest to the Navy, fiber mode area has to be increased by an order of magnitude. The amplifier fiber should be bendable to a reasonably tight diameter and suitable for integration into compact ultra-short pulse laser-amplifier systems that are diode laser pumped, highly efficient and all-fiber. The fiber amplifier should be capable of delivering millijoule ablative energy at high repetition rates with pulses that are compressible to <500 fs duration near the eye-safe wavelength of 1550 nm in a single spatial mode. PHASE I: Conduct research, analysis, and studies on the selected high-energy, short-pulse fiber amplifier design and architecture, develop measures of performance and document results in a final report. The phase I effort should include modeling and simulation results supporting performance claims. The effort should also produce a draft testing methodology that can be used to demonstrate performance of the fiber amplifier system proposed for the phase II effort. PHASE II: Develop the technology advances and methods identified in phase I to demonstrate a proof-of-concept prototype highly efficient, bendable all-fiber amplifier that will deliver single spatial mode pulses at the millijoule energy level with high repetition rates near 1550 nm. Demonstrate pulse compression to <500 fs duration. PHASE III: Develop a fiber amplifier capable of mass production for a variety of civilian and military uses. The final system may be expected to be "hardened" for field use, depending on mission needs. PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Highly efficient fiber amplifiers enable higher average power for USP lasers in smaller footprints. There is a substantial market of USP laser vendors who could seek to enhance their core technology by making use of next generation fiber amplifiers. USP lasers can be utilized in a variety of commercial applications, including surgical, manufacturing, and laser processing. REFERENCES: 2. L. Shah, M. E. Fermann, J. W. Dawson and C. P. J. Barty, "Micromachining with a 50 W, 50 �J, subpicosecond fiber laser system," Opt. Express, vol. 14, no. 25, pp. 12546-12551, 2006. 3. J. Limpert, N. Deguil-Robin, I. Manek-Hönninger, F. Salin, F. Röser, A. Liem, T. Schreiber, S. Nolte, H. Zellmer, A. Tünnermann, J. Broeng, A. Petersson, C. Jakobsen, "High-power rod-type photonic crystal fiber laser," Opt. Express, vol. 13, no. 4, pp. 1055-1058, 2005. 4. G. P. Agrawal, Nonlinear Fiber Optics, Third Edition, San Diego, CA: Academic Press, 2001. KEYWORDS: Ultra-short pulses, Millijoule pulses, High-energy amplifiers, High peak power pulses, Compact fiber amplifiers, Eye-safe fiber amplifiers, Direct diode laser pumping. TPOC: J Thomas Schriempf
|