1 / 44

Kansas Light Source and its Application in Single Attosecond Pulses Generation

Kansas Light Source and its Application in Single Attosecond Pulses Generation. Bing Shan J. R. Macdonald Laboratory Physics Department, Kansas State University. Outline. A high-output, high efficiency femtosecond laser based on a single-stage multipass amplifier

hroy
Download Presentation

Kansas Light Source and its Application in Single Attosecond Pulses Generation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Kansas Light Source and its Application inSingle Attosecond Pulses Generation Bing Shan J. R. Macdonald Laboratory Physics Department, Kansas State University 5/12/2004, Atomic Physics Seminar, KSU

  2. Outline • A high-output, high efficiency femtosecond laser based on a single-stage multipass amplifier • (CLEO 2004, ITuI15, 5/18/2004, 13:00 pm) • Bing Shan, Chun Wang, and Zenghu Chang • Control signal beam sizes to get high gain without damage • In cavity Pockels cell to suppress ASE • Supported researches and experiments in J. R. Macdonald Lab • Generation of XUV Supercontinuum and Single Attosecond Pulses by Half-cycle Polarization Gating • (CLEO 2004, JMA5, 5/17/2004, 9:30 am) • Bing Shan, Shambhu Ghimire, and Zenghu Chang • Ellipticity varying pulse • Polarization gating in high-order harmonic generation • Generate single attosecond pulse and XUV supercontinuum 5/12/2004, Atomic Physics Seminar, KSU

  3. kHz High Power System : Motivations • Muiltipass vs. Regenerative Amplifier • Multipass amplifier has less dispersion than a regen. Good for short pulse CPA. • Its efficiency is lower than a regen. • Single stage vs. two/multi stages • Singe stage is easy to operate, less efficient • Two/multi stage, high efficiency and pulse energy • Our goal: • Short pulse, high pulse energy and efficiency with a single stage, multi-pass amplifier 5/12/2004, Atomic Physics Seminar, KSU

  4. Limitations on Amplifier Output • Damage • Due to signal – limited the final output level • Pump fluence • Amplified Spontaneous Emission (ASE) • Pump level • Number of passes 5/12/2004, Atomic Physics Seminar, KSU

  5. Beam Size Match in Amplifier Small Signal: Localized in high gain area  high total gain, low efficiency, low damage threshold Big Signal: Spread in all pumped area  high efficiency, low gain, high damage threshold Big Signal Small Signal Pump Fluence 5/12/2004, Atomic Physics Seminar, KSU

  6. Pre-amplifier Gain 105 ~ 106100 µJ ~mJ Power Amplifier Gain 100 10s mJ Seed Pulse Oscillator nJ High Power Output Single-pass Gain vs. Signal Beam Size • Pre-amplifier Small beam High Gain, low efficiency Small energy, no damage • Power Amplifier Big beam Low gain, high efficiency Big energy, no damage One Stage Amplifier Pre-amplification + Power Amplification Two-stage Amplifier 5/12/2004, Atomic Physics Seminar, KSU

  7. Kansas Light Source Amplifier Realize Pre- and Power Amplification in a Single Stage Amplifier • Small beam at first several passes: high gain • Change to big beam in the final passes: high power output, high efficiency Beam Change 100 µJ Seed Pulse Amplifier Oscillator nJ High Power Output (mJ) US Patent Pending 10/656,343 5/12/2004, Atomic Physics Seminar, KSU

  8. Kansas Light SourceAmplifier Configuration Bing Shan Feb. 2003 Side View Input Mirror Retro2 Laser Crystal Cavity Mirror1 Cavity Mirror2 Activated Region Pump2 Pump1 Seed Pulse from Oscillator Cavity Mirror1 (End view) 7 5 3 1 2 4 6 Led out in 7 passes Change Beam Height, Size Retro1 Kansas Light SourceAmplifier Configuration 3rd Pass 1st Pass 2nd Pass 5/12/2004, Atomic Physics Seminar, KSU

  9. Control ASE by an in-cavity Pockels Cell By using a in-cavity pockels cell, the ASE has been reduced by 100 times Photo Diode Pockels Cell 2 Pockels Cell 1 S. Satania, Z. Cheng, et al, Opt. Lett. 22, 1562(1997) 5/12/2004, Atomic Physics Seminar, KSU

  10. Output Spectrum Gain Saturation & Spectrum Red Shift Gain depletion: leading edge sees higher gain Chirped pulse: “red” color is at leading edge 36 nm Gain depletion  Higher efficiency and better stability Red Shift  Wider spectrum (shorter pulse duration) 5/12/2004, Atomic Physics Seminar, KSU

  11. Pulse Duration Pulse Duration Shape measured with a SHG FROG Time delay Frequency 5/12/2004, Atomic Physics Seminar, KSU

  12. 4 ft 8 ft Kansas Light Source: A Compact High Power System Oscillator: FemtoLaser Produktion, Pulse energy ~0.5 nJ Stretcher: All reflective, grating, ~1 ps/nm Pump fluence in Amplifier: Peak ~5 J/cm2, lower than normal Final output: 4 mJ/1 kHz or 2.5 mJ/2 kHz, 25 fs, efficiency 26% 5/12/2004, Atomic Physics Seminar, KSU

  13. Summary • A kHz fs laser using a single-stage multipass amplifier (Kansas Light Source) • Output: 4 mJ / 1 kHz or 2.5 mJ / 2 kHz • Pulse duration: 25 fs • Efficiency: 26% • Beam Size Change in the Amplifier • Solved the damage problem in an one-stage amplifier • Advantages: higher energy and efficiency, short pulse • Two Pockels Cell Configuration • ASE was effectively suppressed 5/12/2004, Atomic Physics Seminar, KSU

  14. Advantages of Changing Signal Beam Sizes in Amplifier • Higher output • Avoided the limitation by damage from signal • Better reliability • Lower pump fluence requirement • Big signal size at output • Compact and simple system • One stage, easy to maintain • Save money • Use one stage amplifier instead of two • Better efficiency US Patent Pending 10/656,343 5/12/2004, Atomic Physics Seminar, KSU

  15. Tandem Accelerator Magneto-Optical Trap COLTRIMS LINAC Accelerator ECR Source Kansas Light Source KLS in J. R. Macdonald Lab Kansas Light Source Beamline Setup (Capable of supporting up to 4 experiments simultaneously) Output Configurations (May 2004) Long Pulse 2.5 mJ, 2 kHz Pulse length 25 fs Short Pulse 0.1 + 0.4 mJ, 2 kHz Pulse length 8 fs Courtesy of Al Rankin 5/12/2004, Atomic Physics Seminar, KSU

  16. Supported Researches and Experiments in J. R. Macdonald Lab • On Site Experiments (Inside KLS Lab) • C-E phase stabilization • Hollow-core Fiber • Ellipticity varying pulse and its characterization • High-order Harmonic Generation • HHG from molecules • Generation of attosecond pulse • Measurement of attosecond pulse • X-ray Streak Camera • Spatially Resolved Ionization • Optical Parametrical Amplifier • Supported Experiments • Ionization of molecules (Laser COLTRIMS) • Image potential states in carbon nano-tubes (KLS) • Laser – ion interaction (ECR) • Laser – cold atom interaction (MOT) 5/12/2004, Atomic Physics Seminar, KSU

  17. Hollow Fiber and Polarization gating KLS 30 fs, 0.8 m Hollow-core fiber compressor 1.5 mJ 0.8 mJ Compensator Plate Chirp mirrors ND filter Quartz plate /4 waveplate 5/12/2004, Atomic Physics Seminar, KSU

  18. wavelength Compensating plate I(t) time BBO Crystal I(t) BS Time Delay Stage Computer lens Spectrometer and cold CCD Frequency-resolved optical gating (FROG) Courtesy of Shambhu Ghimire 5/12/2004, Atomic Physics Seminar, KSU

  19. 1-D Spatial Resolution HHG Spectrum MCP & Phosphor BG-39 Filter Gas nozzle Grating 2000 l/mm CCD Slit =2 deg sphere - DC HV Pulser X-ray Filter /4 Waveplate /2 Waveplate High-order Harmonic Generation Gas Nozzle Laser Beam 5/12/2004, Atomic Physics Seminar, KSU

  20. CCD GaAs X-ray Streak Camera Calibration Setup Courtesy of Mahendra Shakya STREAK CAMERA STREAK CAMERA 267nm L2 L1 f=150mm f=100mm 800nm ,25 fs 5/12/2004, Atomic Physics Seminar, KSU

  21. Image Potential States of Carbon nanotubes Delay stage 3hω Beam Splitter λ/2 f = 15 cm f = 17.5 cm Harmonics separator CCD Courtesy of Mikhail Zamkov 5/12/2004, Atomic Physics Seminar, KSU

  22. Momentum Reconstruction of Laser-Molecule Ionization Courtesy of Ali Alnaser Recoil Detector Laser Y Z X Spectrometer supersonic Jet E-Field Intensity : 0.9 -8 *1014 Watt/cm2 790 nm Wavelength 1kHz Repition Rate 5/12/2004, Atomic Physics Seminar, KSU

  23. Y YL X, XL Z Laser beam 55o Mirror ZL Detector Image Lens Ion lens 2D-PSD detector 55o Submitted to JOSA B Courtesy of How Camp 3D Imaging in Above-Threshold Ionization Rate Measurements 5/12/2004, Atomic Physics Seminar, KSU

  24. Generation of XUV Supercontinuum and Single Attosecond Pulses by Half-cycle Gating Bing Shan, Shambhu Ghimire, and Zenghu Chang J. R. Macdonald Laboratory Physics Department, Kansas State University 5/12/2004, Atomic Physics Seminar, KSU

  25. e- Experimental Observation HHG Spectrum: Discrete Spectral Lines E(t) HHG upto 500 eV e- Single Attosecond Pulse HHG Spectrum Super-continuum XUV Sub-cycle Driving Field One Re-collision Process Atto-second Pulse from High-order Harmonic Generation tunnel ionization + re-combination Gas Driving Pulse HHG Pulse Train Half Cycle 5/12/2004, Atomic Physics Seminar, KSU

  26. Attosecond pulse train Single attosecond pulse Polarization Gating by Ellipticity Varying Pulse e- Right-circularly polarized pulse e- e- HHG t Left-circularly polarized pulse P. B. Corkum, N. H. Burnett, and M. Y. Ivanov, Opt. Lett. 19, 1870 (1994) V. T. Platonenko and V. V. Strelkov J. Opt. Soc. Am. B 16, 435 (1999) 5/12/2004, Atomic Physics Seminar, KSU

  27. 0.5 mm Quartz  t = 15 fs @ 800 nm Gate Width (Ellipticity ξ < 0.2) Gate Height (Field Strength at gate center) = 1.2 fs (when  = 8 fs and t = 16 fs) = 0.5 E0(when t = 2 ) Construct the Ellipticity Varying Pulse Ellipticity Varying Pulse E0 5/12/2004, Atomic Physics Seminar, KSU B. Shan, S. Ghimire, Z. Chang, OSA Annual Meeting: Frontier in Optics, Tucson, Arizona, 2003 O. Techerbakoff, E. Me´vel, D. Descamps, J. Plumridge, E. Constant, PRA 68, 043804 (2003)

  28. KLS 30 fs, 0.8 m Hollow-core fiber compressor 1.5 mJ 0.8 mJ Compensator Plate Chirp mirrors MCP & Phosphor ND filter Gas nozzle CCD F=250 mm Quartz plate /4 waveplate Grating • Change Gate Width • Gating vs. non-gating • Gate Height & Width Filter Experiment Setup Input pulse duration tuned by Compensator Plate – minimum ~ 8 fs On-target pulse energy tuned by ND filter – typical intensity 3×1014 W/cm2 5/12/2004, Atomic Physics Seminar, KSU

  29. 1.3 fs ! Change Input Pulse Duration and Gate Width Polarization gate width Gvs. Input pulse duration  (Circular Pulse Separation: t=15 fs) Compensator Plate Thickness 5/12/2004, Atomic Physics Seminar, KSU

  30. 30 40 50 60 70 80 ev Gating vs. Non-gating (a) (b) (c) ~ 100 eV (Si absorption edge) • Quartz axis 45 (gating) OD = 0, I ~ 2.7 X 1014 • Quartz axis 0 (non-gating) OD = 0.7, I ~ 2.5 X 1014 • Quartz axis 0 (non-gating) OD = 0.5, I ~ 4.2 X 1014 Gating ND Filter /4 Waveplate Quartz Non-gating 5/12/2004, Atomic Physics Seminar, KSU

  31. (a) t = 15 fs (0.5 mm Quartz) G = 1.3 fs Eξ = 0= 0.5E0 (b) t = 7.5 fs (0.25 mm Quartz) G = 2.6 fs Eξ = 0= 1.4E0 (a) (b) Gate Width (ξ < 0.2) Gate Height (Field Strength At Gate Center) Half-cycle Gating vs. One-cycle Gating 5/12/2004, Atomic Physics Seminar, KSU

  32. Polarization Gate Half cycle C-E Phase and Signal Intensity Half-cycle Gating Non-gating 8 fs Pulse One-cycle Gating 5/12/2004, Atomic Physics Seminar, KSU

  33. Summary • Half-cycle polarization gating by ellipticity varying pulse; • Supercontinuum XUV and single attosecond pulse at HHG plateau from 30 eV to 80 eV; • Investigation of the gating behavior by input pulse length, separation, gating vs. non-gating. Future work: • Polarization gating with fixed C-E phase 5/12/2004, Atomic Physics Seminar, KSU

  34. Generate Single Attosecond Pulse: Motivation Generation of Atto-second pulse zs as ps fs 10-21 s 10-18 s 10-15 s 10-12 s Time Scale Inside Electronic Inter-atom Molecular Nucleus dynamics Vibration Rotation 5/12/2004, Atomic Physics Seminar, KSU

  35. Previous Work: Single Pulse from Peak Single atto-second pulse is generated at cutoff region by ultrashort driving field (5 fs) with absolute phase locked to 0 5 fs 85 eV 135 ev Attosecond pulse train Single atto-second pulse A. BALTUSKA et.al, Nature 421, 611( 2003) 5/12/2004, Atomic Physics Seminar, KSU

  36. Construct Ellipticity Chirped Pulse: Michelson Conventional Method: Michelson Interferometer 5/12/2004, Atomic Physics Seminar, KSU

  37. How short the Attosecond pulse could be? 5/12/2004, Atomic Physics Seminar, KSU

  38. Hollow-core fiber compressor Compensator Plate Chirp mirrors Adjust Pulse Duration by Compensate Plate Gate Width Under-compensated Long pulse Negatively chirped pulse Short pulse Other optics Compensator plate Over-compensated Long pulse 5/12/2004, Atomic Physics Seminar, KSU

  39. Summary • Technical Approaches • Half–cycle gating has been realized by ellipticity varying pulse • Measure C-E phase and selectively gate the detector • C-E Phase Stabilization • Single Attosecond pulse from every shot • Higher XUV flux • Wider (one-cycle) gating • Higher cutoff & broader supercontinuum 5/12/2004, Atomic Physics Seminar, KSU

  40. (a) (b) 30 40 50 60 70 80 ev Recent Improvements • Bigger fiber: 450 µm ID, 400 ~ 500 µJ  Broader Spectrum • Ar + Ne Gas: Flat Supercontinuum (a) Ne gas (b) Mixed gas: Ne + Ar 5/12/2004, Atomic Physics Seminar, KSU

  41. Spectrum DomainTime Domain 40 30 20 Spectrum (nm) -3 -2 -1 0 1 2 3 Time (fs) XUV Supercontinuum 25 – 45 nm FFT FFT 190 as Fourier Transform of the HHG Spectrums Multiple Attosecond Pulses Single Attosecond Pulse  = 9 fs 190 as 1.4 fs  = 8 fs 5/12/2004, Atomic Physics Seminar, KSU

  42. Characterize the Driving Pulses Two-pulse structure in FROG trace Pulse Duration vs. Compensate Plate Thickness Measured by a SHG FROG 5/12/2004, Atomic Physics Seminar, KSU

  43. Spectrum DomainTime Domain Multiple Attosecond Pulses Single Attosecond Pulse 40 30 20 Spectrum (nm) -3 -2 -1 0 1 2 3 Time (fs) FFT FFT Simulation • Simulation Parameters • Argon Gas Ztarget=1-1.2mm • 0 = 0.85 m I = 1.5×1015 W/cm2w0=30m  = 8 fs t = 15 fs 5/12/2004, Atomic Physics Seminar, KSU

  44. October 10, 200 1 May 4, 2004 5/12/2004, Atomic Physics Seminar, KSU

More Related