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3D Laser pulse shaping for photoinjector applications

3D Laser pulse shaping for photoinjector applications. Yuelin Li Accelerator Systems Division and X-ray Science Division Argonne National Laboratory ylli@aps.anl.gov. Acknowledgement. K. Harkay, K.-J. Kim, and E. Gluskin for strong support

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3D Laser pulse shaping for photoinjector applications

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  1. 3D Laser pulse shaping for photoinjector applications Yuelin Li Accelerator Systems Division and X-ray Science Division Argonne National Laboratoryylli@aps.anl.gov

  2. Acknowledgement • K. Harkay, K.-J. Kim, and E. Gluskin for strong support • J. Lewellen, Y. Sun for discussion and help with GPT simulation • S. Chemrisov for helping with experiments • This work is support by DOE, Office of Basic Science

  3. Outline • The case of pulse shaping: high brightness or low emittance • Thermal/cathode emittance: casted after emission • Emittance growth due to space charge force: can be compensated • Uniform ellipsoidal beam is the key • Pulse shaping techniques • Mechanical: pulse stacking • Physics: self evolving • Phase modulation: • Mechanism • optics and beam simulation • Progress at ANL: A proof of principle experiment • Measurement method • Phase tailoring procedure • Results • Summary

  4. Outline • The case of pulse shaping: high brightness or low emittance • Thermal/cathode emittance: casted after emission • Emittance growth due to space charge force: can be compensated • Uniform ellipsoidal beam is the key • Pulse shaping techniques • Mechanical: pulse stacking • Physics: self evolving • Phase modulation: • Mechanism • optics and beam simulation • Progress at ANL: A proof of principle experiment • Measurement method • Phase tailoring procedure • Results • Summary and acknowledgement

  5. { The case of pulse shaping • The case of pulse shaping: • Theory of emittance compensation • Emittance growth due to space charge force can be compensated if the space charge force is linear • Carlsten, NIMA 285, 313, (1989) • Serafini and Rosenzweig, PRE 55, 7565 (1997) • Homogeneous ellipsoidal beam is the key • Uniform electron density distribution in a ellipsoid • Has linear space charge force (M. Reiser, Theory and Design of Charged Particle Beams, Wiley, New York.)

  6. Space charge force distribution: three geometries Cylindrical 3D Gaussian H. Ellipsodial

  7. Outline • The case of pulse shaping: high brightness or low emittance • Thermal/cathode emittance: casted after emission • Emittance growth due to space charge force: can be compensated • Uniform ellipsoidal beam is the key • Pulse shaping techniques • Mechanical: pulse stacking • Physics: self evolving • Phase modulation: • Mechanism • optics and beam simulation • Progress at ANL: A proof of principle experiment • Measurement method • Phase tailoring procedure • Results • Summary

  8. Pulse stacking • Excellent for longitudinally flat topped pulse • Interferometer setup • C. Sider, Appl. Opt. 37, 5302 (1998). • Bi-fringence crystals • C. S. Zhou, et al., Applied Optics 46, 1 - 5 (2007). • I.V. Bazarov, D.G. Ouzounov, B.M. Dunham, Phys. Rev. ST AB 11, 040702 (2008). • For uniform ellipsoidal pulse generation: very complicated • First beam simulation by Limborg • C. Limborg-Deprey and P. Bolton, Nucl. Instrum. Methods A 557, 106 (2006). • Design exists, but with low efficiency • H. Tomizawa, private communication).

  9. Self-evolution of the a pancake beam • Pro • Easy: Need a short pulse (100 fs) with initial parabolic transverse distribution, no longi shaping needed • Con • Cannot put too many charges: image charge will distort the beam • Pancake geometry thus larger transverse size: larger cathode emittance to start with • L. Serafini, AIP Conf. Proc. 413, 321 (1997). • O. J. Luiten et al, Phys. Rev. Lett. 93, 094802 (2004). • B. J. Claessens, Phys. Rev. Lett. 95, 164801 (2005). • J. B. Rosenzweig et al., Nucl. Instrum. Methods A 557, 87 (2006). • P. Musumeci, et al., Phys. Rev. Lett. 100, 244801 (2008).

  10. Phase: f(w) Amplitude: A(w) Phase: w(t) Amplitude: A(t) Size: r(t) Amplitude: A(t) = Chromatic dispersion Frequency domain Time domain Spatiotemporal Pulse shaping: 3D laser pulse shaping to generate an ellipsoidal beam • Difficulties • Simultaneous evolving longitudinal and transverse profiles • Homogeneous in 3-D • Actually a 2-D problem due to rotation symmetry • Hope: coupling between time and space via chromatic dispersion

  11. Phase tailoring dw t Chromatic dispersion for ellipsoidal pulse Chromatic dispersion + Radius modulation

  12. Can an ellipsoidal pulse be generated? • A EM pulse can be written as • An ellipsoidal pulse • Chromatic Dispersion • Gaussian beam • Therefore Y. Li and J. Lewellen, PRL 100, 078401(2008)

  13. Numerical calculation: Fourier optics method • Full wave optics (Fresnel diffraction) adapted from Kempe et al. (JOSA B 9, 1158 (1992)) • Group velocity dispersion and group velocity delay effect considered up to the second order Kempe et al.,JOSA B 9, 1158 (1992)

  14. The 3D laser pulse at the focal plane of a lens Dw/w=8%, 4%, 2%, 1%, and 0.5%, a0=25 mm, a0=25, 12, 6, 4, and 2 mm, Dw/w=8%, f=150 mm, 249 nm, 12 ps FW Li, Lewellen and Chemerisov, PRSTAB 12, 020702 (2009).

  15. Performance at 1 nC very promising in simulation Emittance Spatiotemporal profile Y. Li and J. Lewellen, PRL 100, 078401(2008) Simulation condition for LCLS from: M. Ferrario et. al., Proc. EPAC 2000, p. 1642.

  16. Outline • The case of pulse shaping: high brightness or low emittance • Thermal/cathode emittance: casted after emission • Emittance growth due to space charge force: can be compensated • Uniform ellipsoidal beam is the key • Pulse shaping techniques • Mechanical: pulse stacking • Physics: self evolving • Phase modulation: • Mechanism • optics and beam simulation • Progress at ANL: A proof of principle experiment • Measurement method • Phase tailoring procedure • Results • Summary

  17. C D AL SF ZSL PP ODL A proof of principle experiment • Experimental setup • 800 nm laser, 1 kHz, 10 nJ per pulse, 40 nm bandwidth • ZnSe lens as the focal lens for high dispersion • 25-mm diameter, 88.9-mm radius of curvature, and 2.9-mm center thickness, Janos Technology, A1204-105, • Dispersion 250 fs2/mm at 800 nm ) • DAZZLER as the phase modulator • Achromatic lens for transport PP: pulse picker; D: AOPDF; SF: achromatic spatial filter; ZSL: ZnSe lens; AL: achromatic image relay lens; ODL: optical delay line; C: camera. Y. Li and S. Chemerisov, Opt. Lett. 33, 1996 (2008); Li, Lewellen and Chemerisov, PRSTAB 12, 020702 (2009).

  18. 3D mapping method • The signal recorded on the camera is • If probe is much shorter than the main pulse • Measuring the contrast ratio C(t,r), and integrated probe intensity Ip(r), Interference term Main beam profile at t Y. Li and S. Chemerisov, Opt. Lett. 33, 1996 (2008). Li, Lewellen and Chemerisov, PRSTAB 12, 020702 (2009).

  19. Data processing example Ip Raw Fringe map im

  20. Phase and amplitude modulation viaAcousto-optic Programmable Dispersive Filter (DAZZLER) • A device widely used in laser and optical research • F. Verluise, V. Laude, Z. Cheng, Ch. Spielmann, and P. Tournois, Opt. Lett. 25, 575 (2000). • DAZZLER and similar phase modulation device have been applied to photoinjector related laser pulse shaping for cylindrical pulse • H. Tomizawa et. al., Nucl. Instrum. Methods A 557, 117 (2006). • J. Yang, et al., J. Appl. Phys. 92, 1608 (2002). • S. Cialdi, et al., Appl. Opt. 46, 4959 (2007). UV version available • UV version available • http://fastlite2.siteo.com/en/page15.xml • T. Oksenhendler, CLEO 07 266 nm

  21. Generating the desired phase and amplitude modulation • Calculate the time domain amplitude and phase • Fourier transform for frequency domain for desire spectrum • Take a spectrum of the laser and calculate the spectrum to load to the DAZZLER • Load the spectrum and phase to the DAZZLER Y. Li and S. Chemerisov, Opt. Lett. 33, 1996 (2008).

  22. Results for a Gaussian beam with different aperture size Input beam • Excellent between data and simulation • Work for the future • Demonstration in UV with larger beam • Beam experiment Data Sim Comp Y. Li and S. Chemerisov, Opt. Lett. 33, 1996 (2008). Li, Lewellen and Chemerisov, PRSTAB 12, 020702 (2009).

  23. Effect of residual linear chirp Data • Beam radius: 1/e2 width of 3 mm Sim Comp Li, Lewellen and Chemerisov, PRSTAB 12, 020702 (2009).

  24. Outline • The case of pulse shaping: high brightness or low emittance • Thermal/cathode emittance: casted after emission • Emittance growth due to space charge force: can be compensated • Uniform ellipsoidal beam is the key • Pulse shaping techniques • Mechanical: pulse stacking • Physics: self evolving • Phase modulation: • Mechanism • optics and beam simulation • Progress at ANL: A proof of principle experiment • Measurement method • Phase tailoring procedure • Results • Summary

  25. Summary • Current status • Laser pulse shaping may generate 3D shaped pulses, potentially uniform ellipsoid • A 3D mapping method is developed • Issues • High rep rate and longer pulse duration: longer crystals • Fastlite, private communications • Future plan • Generating a flat topped beam as input • Demonstration in UV • Beam generation

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