Henry Kapteyn Portrait
Professor • Fellow - JILA
Physics
henry.kapteyn@colorado.edu
(303) 492-8198

Office: JILA A703

Research Interests:

Ultrafast laser technology, ultrafast dynamics in Molecular and materials systems, and development of tabletop coherent x-ray sources.

My primary interest is in developing-- and making use of-- new tabletop "x-ray laser" light sources. 20 years ago, the process of "high order harmonic generation" (HHG) was discovered, where an intense short pulse laser focused into a gas at high intensity was shown to produce light at very high-order harmonics of the driving laser . By implementing this technique using new laser technologies we developed, it became possible to drive this process to an extreme, generating x-ray light that still retains the coherence of the driving laser. However, to implement this tehcnique in a useful way requires an understanding of nonlinear optics in a very different regime than has been studied in the past, necessitating a new way of thinking about phase matching of nonlienar optical processes. During the past decade, we have developed a variety of techniques that allow us to phase-match and quasi-phase match the HHG process. The result is a useful tabletop coherent x-ray source that has applications in in wide variety of scinetific investigations, as well as for technological applications such as nanoscale imaging. The very short-pulse (femtosecond-to-attosecond) nature of these sources makes them useful for studies of ultrafast dynamics, and we have used this source for studies of x-ray induced molecular dissociation, for studies of heat transport on the nanoscale, and for studies of magnetism dynamics (among other things).

Selected Publications:

  1. M. E. Siemens, Q. Li, R. Yang, K. A. Nelson, E. H. Anderson, M. M. Murnane, and H. C. Kapteyn, "Quasi-ballistic thermal transport from nanoscale interfaces observed using ultrafast coherent soft X-ray beams," Nat Mater advance online publication, 10.1038/nmat2568 (2009).
  2. T. Popmintchev, M. C. Chen, A. Bahabad, M. Gerrity, P. Sidorenko, O. Cohen, I. P. Christov, M. M. Murnane, and H. C. Kapteyn, "Phase matching of high harmonic generation in the soft and hard X-ray regions of the spectrum," Proceedings Of The National Academy Of Sciences Of The United States Of America 106(26), 10516-10521 (2009).
  3. A. S. Sandhu, E. Gagnon, R. Santra, V. Sharma, W. Li, P. Ho, P. Ranitovic, C. L. Cocke, M. M. Murnane, and H. C. Kapteyn, "Observing the Creation of Electronic Feshbach Resonances in Soft X-ray-Induced O-2 Dissociation," Science 322(5904), 1081-1085 (2008).
  4. R. L. Sandberg, C. Y. Song, P. W. Wachulak, D. A. Raymondson, A. Paul, B. Amirbekian, E. Lee, A. E. Sakdinawat, C. La-O-Vorakiat, M. C. Marconi, C. S. Menoni, M. M. Murnane, J. J. Rocca, H. C. Kapteyn, and J. W. Miao, "High numerical aperture tabletop soft x-ray diffraction microscopy with 70-nm resolution," Proceedings of the National Academy of Sciences of the United States of America 105(1), 24-27 (2008).
  5. W. Li, X. B. Zhou, R. Lock, S. Patchkovskii, A. Stolow, H. C. Kapteyn, and M. M. Murnane, "Time-Resolved Dynamics in N2O4 Probed Using High Harmonic Generation," Science 322(5905), 1207-1211 (2008).
  6. X. H. Zhang, A. L. Lytle, T. Popmintchev, X. B. Zhou, H. C. Kapteyn, M. M. Murnane, and O. Cohen, "Quasi-phase-matching and quantum-path control of high-harmonic generation using counterpropagating light," Nature Physics 3(4), 270-275 (2007).
  7. H. Kapteyn, O. Cohen, I. Christov, and M. Murnane, "Harnessing attosecond science in the quest for coherent X-rays," Science 317(5839), 775-778 (2007).
  8. E. Gagnon, P. Ranitovic, A. Paul, C. L. Cocke, M. M. Murnane, H. C. Kapteyn, and A. S. Sandhu, "Soft x-ray driven femtosecond molecular dynamics," Science 317(5843), 1374-1378 (2007).
  9. L. Miaja-Avila, C. Lei, M. Aeschlimann, J. L. Gland, M. M. Murnane, H. C. Kapteyn, and G. Saathoff, "Laser-assisted photoelectric effect from surfaces," Physical Review Letters 97(11), 113604 (2006).
  10. H. C. Kapteyn, M. M. Murnane, and I. P. Christov, "Extreme Nonlinear Optics: Coherent X Rays from Lasers," Physics Today 58(3), 9-44 (2005).
  11. A. Paul, R. A. Bartels, R. Tobey, H. Green, S. Weiman, I. P. Christov, M. M. Murnane, H. C. Kapteyn, and S. Backus, "Quasi-phase-matched generation of coherent extreme-ultraviolet light," Nature 421(6918), 51-54 (2003).
  12. R. A. Bartels, A. Paul, H. Green, H. C. Kapteyn, M. M. Murnane, S. Backus, I. P. Christov, Y. W. Liu, D. Attwood, and C. Jacobsen, "Generation of spatially coherent light at extreme ultraviolet wavelengths," Science 297(5580), 376-378 (2002).
  13. R. K. Shelton, L. S. Ma, H. C. Kapteyn, M. M. Murnane, J. L. Hall, and J. Ye, "Phase-coherent optical pulse synthesis from separate femtosecond lasers," Science 293(5533), 1286-1289 (2001).
  14. S. Backus, R. Bartels, S. Thompson, R. Dollinger, H. C. Kapteyn, and M. M. Murnane, "High-efficiency, single-stage 7-kHz high-average-power ultrafast laser system," Optics Letters 26(7), 465-467 (2001).
  15. R. Bartels, S. Backus, E. Zeek, L. Misoguti, G. Vdovin, I. P. Christov, M. M. Murnane, and H. C. Kapteyn, "Shaped-pulse optimization of coherent emission of high-harmonic soft X-rays," Nature 406(6792), 164-166 (2000).
  16. A. Rundquist, C. G. Durfee III, S. Backus, C. Herne, Z. Chang, M. M. Murnane, and H. C. Kapteyn, "Phase-matched Generation of Coherent Soft X-rays," Science 280(5368), 1412-1415 (1998).
  17. Z. H. Chang, A. Rundquist, H. W. Wang, M. M. Murnane, and H. C. Kapteyn, "Generation of coherent soft x rays at 2.7 nm using high harmonics (vol 79, pg 2967, 1997)," Physical Review Letters 80(8), 1795-1795 (1998).
  18. I. P. Christov, M. M. Murnane, and H. C. Kapteyn, "High-harmonic generation of attosecond pulses in the ''single- cycle'' regime," Physical Review Letters 78(7), 1251-1254 (1997).
  19. J. Zhou, J. Peatross, M. M. Murnane, H. C. Kapteyn, and I. P. Christov, "Enhanced High Harmonic Generation using 25 Femtosecond Laser Pulses," Physical Review Letters 76(5), 752-755 (1996).
  20. J. P. Zhou, C. P. Huang, M. M. Murnane, and H. C. Kapteyn, "Amplification of 26 fs, 2 TW pulses near the gain-narrowing limit in Ti:sapphire," Optics Letters 20(1), 64 (1995).
  21. S. Backus, J. Peatross, C. P. Huang, H. C. Kapteyn, and M. M. Murnane, "Ti:Sapphire Amplifier Producing Millijoule-Level, 21 fs Pulses at 1 kHz," Optics Letters 20(19), 2000 (1995).
  22. J. P. Zhou, G. Taft, C. P. Huang, M. M. Murnane, H. C. Kapteyn, and I. P. Christov, "Pulse Evolution in a Broad-Bandwidth Ti-Sapphire Laser," Optics Letters 19(15), 1149-1151 (1994).
  23. M. T. Asaki, C. P. Huang, D. Garvey, J. Zhou, H. C. Kapteyn, and M. M. Murnane, "Generation of 11-fs pulses from a modelocked Ti:sapphire laser," Optics Letters 18, 977 (1993).
  24. A. Sullivan, H. Hamster, H. C. Kapteyn, S. Gordon, W. White, H. Nathel, R. J. Blair, and R. W. Falcone, "Multi-Terawatt 100 Femtosecond Laser," Optics Letters 16(18), 1406-1408 (1991).
  25. M. M. Murnane, H. C. Kapteyn, M. D. Rosen, and R. W. Falcone, "Ultrafast X-Ray Pulses from Laser-Produced Plasmas," Science 251(4993), 531-536 (1991).