DLA Laser Working Group Close Out Report

Transcription

1 DLA Laser Working Group Close Out Report Co- Chairs: Jay Dawson Bob Byer Contributors: Peter Moulton, KonstanNn Vodopyanov, Ken Soong, Charles Rudy, Stephen Wolf, Eric Cormier, Igor Makasyuk, Eric Colby, Gil Travish, MarNn Morf, Rodian Tikhoplav, Behnam Montazeri, James Harris, Olav Solgaard

2 Outline Requirements Laser state of the art summary Base- line design and opnons Highest priority challenges to address in base- line design(s) PotenNal game- changers White Paper

3 Requirements (TeV, other apps lower power) Requirement Woodpile PCF Fiber Gra6ngs Resonant Structure Pulse energy 200nJ 1µJ 10µJ 1-10µJ Average Power 20W, 200 W (goal) 100W, 1kW (goal) 1kW, 10kW (goal) 1kW Wavelength >2 µm, longer pref 1µm, longer pref? Not important Not important Pulse widths 1ps 1ps ps ps CEP Locking RepeNNon Rate <1 degree opncal phase angle 100 MHz, 1 GHz (goal) <1 degree opncal phase angle 100 MHz, 1 GHz (goal) <1 degree opncal phase angle 100 MHz, 1 GHz (goal) <1 degree opncal phase 100MHz to 1GHz Wall Plug Efficiency 30% min, 40% Goal 30% min, 40% Goal 30% min, 40% Goal 30% min, 40% Goal Beam quality Maintain eff. req. when beam is coupled Maintain eff. req. when beam is coupled Top Hat Maintain eff. req. when beam is coupled Intensity Noise Consistent with CEP phase angle req Consistent with CEP phase angle req Consistent with CEP phase angle req Consistent with CEP phase angle req Pulse Shape Flat- top super- Gaussian (m=?, flatness?) Flat- top super- Gaussian (m=?, flatness?) Flat- top super- Gaussian (m=?, flatness?) Flat followed by ramp

4 Fiber lasers are desirable because they are a simple-to-use, lowmaintenance, compact source of high-brightness, high-power laser light with wall plug efficiencies in excess of 30%

5 In the CW realm >10kW is commercial!

6 At 1µm, fiber lasers offer near term solunons with performance up to a ~1 mj in a single aperture CPA system Mode-Locked* Fiber Oscillator IMRA Fianium Pulse Stretcher Pre**Amplifiers Raydiance Calmar * Fiber oscillator may contain control 6electronics to lock oscillator RF or optical phase to external reference High Energy/ High Average Power Amplifier Pulse Compressor Commercial systems ~ 50µJ - Ongoing energy scaling - Applications requiring<1mj/1ps, will probably be able to buy commercial in a few years Will review state of the art shortly Numerous pulse stretcher options Good injection seed lasers <<1 ps needs additional development Pulses may have some significant pedestal, but >90% of energy in main pulse Flat top pulses may need minimal development CEP a custom option ** Amplifier chain will contain components such as optical isolators, band pass filters and temporal modulators to gate out ASE between pulses and to control pulse rep rate

7 CEP is established technology

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12 Degenerate OPO offers a pathway to longer wavelengths

13 State of the Art Summary Fiber lasers at 1µm are well developed Required pulse energies, pulse widths and efficiencies easily ajainable CEP an opnon Commercial companies make lasers Scaling to kw harder but conceivable Fiber laser at 2µm are up and coming quickly CW power levels of kw demonstrated CEP demonstrated in 2µm MLL More development needed to mature technology, but path is straighkorward Frequency conversion to longer wavelengths Degenerate OPO a promising path forward Significantly more work needed here to mature concepts Possible applicanons in the injector (harder to implement, efficiency hit so OK on in limited use overall)

14 Reference frequency Baseline Design (0) Carrier phase locked oscillator 100 MHz (1GHz goal), 1ps/0.44THz Or 200fs/2.2THz Clock distribunon system Local carrier phase locked oscillator 100 MHz (1GHz goal), 1ps/0.44THz Or 200fs/2.2THz Pre- amplifier 1xN splijer Band pass filter Phase controllers (woofer/tweeter) Control loop Stretcher (x ps) Pre- amplifier (1 or 2) Power amplifier Compressor/ Dispersion Controller Shield Delivery opncs or Fibers and/or mode converter Vacuum Phase sensor *Hard Total units: MxN

15 Reference frequency Baseline Design (1) Carrier phase locked oscillator 100 MHz (1GHz goal), 1ps/0.44THz Or 200fs/2.2THz Clock distribunon system Local carrier phase locked oscillator 100 MHz (1GHz goal), 1ps/0.44THz Or 200fs/2.2THz Pre- amplifier 1xN splijer Band Pass Filter Phase controllers (woofer/tweeter) Control loop Stretcher (x ps) Pre- amplifier (1 or 2) Power amplifier Delivery opncs or Fibers and/or mode converter Shield Compressor/ Dispersion Controller Vacuum Phase sensor *Hard Total units: MxN

16 Reference frequency Baseline Design (2) Carrier phase locked oscillator 100 MHz (1GHz goal), 1ps/0.44THz Or 200fs/2.2THz Clock distribunon system Local carrier phase locked oscillator 100 MHz (1GHz goal), 1ps/0.44THz Or 200fs/2.2THz Pre- amplifier Phase controllers (woofer/tweeter) Control loop Stretcher (x ps) Pre- amplifier (1 or 2) Power amplifier Compressor/ Dispersion Controller Delivery opncs or Fibers and/or mode converter 1xN splijer Phase sensor Shield Vacuum *Hard Total units: MxN

17 Toughest Challenges (R&D priorines) Timing of the overall structure Phase sensor Master Nming circuit Short pulses at kw powers (fiber amplifier challenge) Delivery from laser to structure (through shield and vacuum wall) High energy, high average power transport Dispersion control Mode matching to both laser and structure Ability to operate in a high radianon environment Cost control Ensuring overall system efficiency/operanon and maintenance cost Capital costs Stretcher and compressor for pulses How lijle can we stretch and make a good pulse Compact robust stretcher and compressor

18 PotenNal Game- Changes Shorter fibers (materials with higher doping and/or higher thermal conducnvity) Efficient long wavelength diode lasers (>1500nm) Improved lithography to permit 1µm operanon of the lasers

19 White Paper Outline (10 pages) Discussion of requirements (Jay, 1 page) Current state of the art in laser technology Overview of lasers (Bob B, 1.5 pages) Fiber lasers (Peter M, 3 pages) Baseline design and opnons ( C. Rudy, 2 pages) R&D Challenges and OpportuniNes (E. Cormier, 1.5 pages) PotenNal Gamechangers (0.5 pages, K. Soong) Summary (0.5 pages, Jay) DUE DATE: October 17 th or earlier Reminder October 10 th

20 QuesNons for other groups Materials development Injector?

21 Extra Credit Pulsed that can be shaped temporally in Nme on the <1ps scale