FY2005 Progress Summary and FY2006 Program Plan Statement of Work and Deliverables for Development of High Average Power Diode-Pumped Solid State Lasers, and Complementary Technologies, for Applications in Energy and Defense

Ebbers, C

Lawrence Livermore National Laboratory

关键词: Aluminium;    Testing;    Vanes;    Harmonic Generation;    Aerodynamics;   

DOI  :  10.2172/899419
RP-ID  :  UCRL-TR-220224
RP-ID  :  W-7405-ENG-48
RP-ID  :  899419

美国|英语

来源: UNT Digital Library

【 摘 要 】

The primary focus this year was to operate the system with two amplifiers populated with and pumped by eight high power diode arrays. The system was operated for extended run periods which enabled average power testing of components, diagnostics, and controls. These tests were highly successful, with a demonstrated energy level of over 55 joules for 4 cumulative hours at a repetition rate of 10 Hz (average power 0.55 kW). In addition, high average power second harmonic generation was demonstrated, achieving 227 W of 523.5 nm light (22.7 J, 10 Hz, 15 ns, 30 minutes) Plans to achieve higher energy levels and average powers are in progress. The dual amplifier system utilizes a 4-pass optical arrangement. The Yb:S-FAP slabs were mounted in aerodynamic aluminum vane structures to allow turbulent helium gas flow across the faces. Diagnostic packages that monitored beam performance were deployed during operation. The laser experiments involved injecting a seed beam from the front end into the system and making four passes through both amplifiers. Beam performance diagnostics monitored the beam on each pass to assess system parameters such as gain and nearfield intensity profiles. This year, an active mirror and wavefront sensor were procured and demonstrated in an off-line facility. The active mirror technology can correct for low order phase distortions at user specified operating conditions (such as repetition rates different than 10 Hz) and is a complementary technology to the static phase plates used in the system for higher order distortions. A picture of the laser system with amplifier No.2 (foreground) and amplifier No.1 (background) is shown in Fig. 1.0.1.1. The control system and diagnostics were recently enhanced for faster processing and allow remote operation of the system. The growth and fabrication of the Yb:S-FAP slabs constituted another major element of our program objectives. Our goal was to produce at least fourteen 4x6 cm2 crystalline slabs. These goals were met. Nine crystal boules were successfully grown to produce 14 slabs. In addition, we have prepared the way to scale the Yb:S-FAP crystals to the next growth diameter (10-inch diameter as opposed to 7-inch diameter). An outside contract was placed with Northrop-Grumman to scaleup the Yb:S-FAP crystal size. The following sections discuss the above accomplishments in more technical detail and are followed by plans and a budget request for FY2006.