Ultrashort optical pulses have time durations around 10-12-10-15 seconds, which can provide unprecedented time resolution, spectral bandwidth, and peak intensity. They have been employed in a variety of applications, ranging from time-resolved spectroscopy, optical fiber communications, biomedical imaging, to high-field physics. As a result, there is a growing demand on measurement techniques of ultrashort optical pulses. However, there is no existing photodetector fast enough to directly resolve the envelopes of femtosecond optical pulses, not to mention the phase (or fringe density) evolution. All-optical methods relying on some nonlinear interaction of the unknown optical pulse itself to create ultrashort “gate function”, are usually required. We proposed and experimentally demonstrated the modified interferometric field autocorrelation (MIFA) method to completely retrieve the amplitude and phase profiles of ultrashort optical pulses by using thick nonlinear crystals. MIFA method is particularly attractive because of: (1) high sensitivity, (2) simplified and cost-effective configuration, and (3) free of time-consuming iterative algorithm. We have achieved an unprecedented sensitivity of 2.7 10-9 mW2, improving on the previous record of self-referenced ultrashort pulse measurement by 800 times. The method also successfully characterized 8-fs visible pulse, proving its great potential in measuring few-to-single cycle pulses.

1. N. Dudovich, D. Oron, and Y. Silberberg, "Single-pulse coherently controlled nonlinear Raman spectroscopy and microscopy," Nature 418, 512-514 (2002).
2. H. -P. Chuang, and C. -B. Huang, "Generation and delivery of 1-ps optical pulses with ultrahigh repetition-rates over 25-km single mode fiber by a spectral line-by-line pulse shaper," Optics Express 18, 24003-24011 (2010).
3. P. Antoine, A. Lhuillier, and M. Lewenstein, "Attosecond pulse trains using high-order harmonics," Physical Review Letters 77, 1234-1237 (1996).
4. A. M. Weiner, Ultrafast Optics (Wiley, 2009).
5. C. Dorrer, and I. Kang, "Complete temporal characterization of short optical pulses by simplified chronocyclic tomography," Optics Letters 28, 1481-1483 (2003).
6. A. Monmayrant, S. Weber, and B. Chatel, "A newcomer's guide to ultrashort pulse shaping and characterization," Journal of Physics B-Atomic Molecular and Optical Physics 43 , 103001 (34pp) (2010).
7. C. Iaconis, and I. A. Walmsley, "Spectral phase interferometry for direct electric-field reconstruction of ultrashort optical pulses," Optics Letters 23, 792-794 (1998).
8. R. Trebino, P. Bowlan, P. Gabolde, X. Gu, S. Akturk, and M. Kimmel, "Simple devices for measuring complex ultrashort pulses," Laser & Photonics Reviews 3, 314-342 (2009).
9. A. Zumbusch, G. R. Holtom, and X. S. Xie, "Three-dimensional vibrational imaging by coherent anti-Stokes Raman scattering," Physical Review Letters 82, 4142-4145 (1999).
10. S. -D. Yang, A. M. Weiner, K. R. Parameswaran, and M. M. Fejer, "Ultrasensitive second-harmonic generation frequency-resolved optical gating by aperiodically poled LiNbO3 waveguides at 1.5 mm," Optics Letters 30, 2164-2166 (2005).
11. H. -X. Miao, S. -D. Yang, C. Langrock, R. V. Roussev, M. M. Fejer, and A. M. Weiner, "Ultralow-power second-harmonic generation frequency-resolved optical gating using aperiodically poled lithium niobate waveguides [Invited]," Journal of the Optical Society of America B-Optical Physics 25, A41-A53 (2008).
12. S. -D. Yang, C. -S. Hsu, S. -L. Lin, H. -X. Miao, C. -B. Huang, and A. M. Weiner, "Direct spectral phase retrieval of ultrashort pulses by double modified one-dimensional autocorrelation traces," Optics Express 16, 20617-20625 (2008).
13. S. -D. Yang, A. M. Weiner, K. R. Parameswaran, and M. M. Fejer, "400-photon-per-pulse ultrashort pulse autocorrelation measurement with aperiodically poled lithium niobate waveguides at 1.55 mm," Optics Letters 29, 2070-2072 (2004).
14. G. Stibenz, and G. Steinmeyer, "Interferometric frequency-resolved optical gating," Optics Express 13, 2617-2626 (2005).
15. G. Stibenz, and G. Steinmeyer, "Structures of interferometric frequency-resolved optical gating," IEEE Journal of Selected Topics in Quantum Electronics 12, 286-296 (2006).
16. S. -D. Yang, H. -X. Miao, Z. Jiang, A. M. Weiner, K. R. Parameswaran, and M. M. Fejer, "Ultrasensitive nonlinear measurements of femtosecond pulses in the telecommunications band by aperiodically poled LiNbO3 waveguides," Applied Optics 46, 6759-6769 (2007).
17. G. Imeshev, M. A. Arbore, M. M. Fejer, A. Galvanauskas, M. Fermann, and D. Harter, "Ultrashort-pulse second-harmonic generation with longitudinally nonuniform quasi-phase-matching gratings: pulse compression and shaping (vol B17, pg 304, 2000)," Journal of the Optical Society of America B-Optical Physics 18, 121-121 (2001).
18. R. Trebino, K. W. DeLong, D. N. Fittinghoff, J. N. Sweetser, M. A. Krumbugel, B. A. Richman, and D. J. Kane, "Measuring ultrashort laser pulses in the time-frequency domain using frequency-resolved optical gating," Review of Scientific Instruments 68, 3277-3295 (1997).
19. R. Trebino, Frequency-Resolved Optical Gating: The Measurement of Ultrashort Laser Pulse (Kluwer Academic Publisher, Boston, MA, 2000).
20. L. Lepetit, G. Cheriaux, and M. Joffre, "Linear techniques of phase measurement by femtosecond spectral interferometry for applications in spectroscopy," Journal of the Optical Society of America B-Optical Physics 12, 2467-2474 (1995).
21. T. M. Shuman, M. E. Anderson, J. Bromage, C. Iaconis, L. Waxer, and I. A. Walmsley, "Real-time SPIDER: ultrashort pulse characterization at 20 Hz," Optics Express 5, 134-143 (1999).
22. J. R. Birge, R. Ell, and F. X. Kartner, "Two-dimensional spectral shearing interferometry for few-cycle pulse characterization," Optics Letters 31, 2063-2065 (2006).
23. B. von Vacano, T. Buckup, and M. Motzkus, "Shaper-assisted collinear SPIDER: fast and simple broadband pulse compression in nonlinear microscopy," Journal of the Optical Society of America B-Optical Physics 24, 1091-1100 (2007).
24. C. Dorrer, B. de Beauvoir, C. Le Blanc, S. Ranc, J. P. Rousseau, P. Rousseau, and J. P. Chambaret, "Single-shot real-time characterization of chirped-pulse amplification systems by spectral phase interferometry for direct electric-field reconstruction," Optics Letters 24, 1644-1646 (1999).
25. S. -D. Yang, and Y. -Y. Huang, "Even-order spectral phase retrieval by modified interferometric field autocorrelation trace," IEEE LEOS Annual Meeting Conference Proceedings, ThT3, 844-845 (2007).
26. S. -D. Yang, S. -L. Lin, and Y. -Y. Huang, "Complete Spectral Phase Retrieval by Modified Interferometric Field Autocorrelation Traces," Conference on Lasers and Electro-Optics & Quantum Electronics and Laser Science Conference, JWA58, 2802-2803 (2008).
27. S. -D. Yang, C. -S. Hsu, S. -L. Lin, Y. -S. Lin, C. Langrock, and M. M. Fejer, "Ultrasensitive direct-field retrieval of femtosecond pulses by modified interferometric field autocorrelation," Optics Letters 34, 3065-3067 (2009).
28. C. Ventalon, J. M. Fraser, and M. Joffre, "Time-domain interferometry for direct electric field reconstruction of mid-infrared femtosecond pulses," Optics Letters 28, 1826-1828 (2003).
29. Y. Coello, V. V. Lozovoy, T. C. Gunaratne, B. W. Xu, I. Borukhovich, C. H. Tseng, T. Weinacht, and M. Dantus, "Interference without an interferometer: a different approach to measuring, compressing, and shaping ultrashort laser pulses," Journal of the Optical Society of America B-Optical Physics 25, A140-A150 (2008).
30. H. S. Chan, Z. M. Hsieh, W. H. Liang, A. H. Kung, C. K. Lee, C. J. Lai, R. P. Pan, and L. H. Peng, "Synthesis and Measurement of Ultrafast Waveforms from Five Discrete Optical Harmonics," Science 331, 1165-1168 (2011).
31. J. Mohring, T. Buckup, and M. Motzkus, "Shaper-assisted ultraviolet cross correlator," Optics Letters 35, 1816-1818 (2010).
32. A. Galler, and T. Feurer, "Pulse shaper assisted short laser pulse characterization," Applied Physics B-Lasers and Optics 90, 427-430 (2008).
33. Z. M. Hsieh, C. J. Lai, W. H. Liang, T. T. Tang, W. J. Chen, R. P. Pan, C. L. Pan, and A. H. Kung, "Pulse Shaper Assisted Characterization of Single-cycle Optical Pulses," Conference on Lasers and Electro-Optics and Quantum Electronics and Laser Science Conference, Vols 1, 550-551 (2009).
34. K. R. Parameswaran, R. K. Route, J. R. Kurz, R. V. Roussev, M. M. Fejer, and M. Fujimura, "Highly efficient second-harmonic generation in buried waveguides formed by annealed and reverse proton exchange in periodically poled lithium niobate," Optics Letters 27, 179-181 (2002).
35. C. Langrock, M. M. Fejer, I. Hard, and M. E. Fermann, "Generation of octave-spanning spectra inside reverse-photon-exchanged periodically poled lithium niobate waveguides," Optics Letters 32, 2478-2480 (2007).
36. A. M. Weiner, "Femtosecond pulse shaping using spatial light modulators," Review of Scientific Instruments 71, 1929-1960 (2000).
37. A. Yabushita, Y. H. Lee, and T. Kobayashi, "Development of a multiplex fast-scan system for ultrafast time-resolved spectroscopy," Review of Scientific Instruments 81 (2010).
38. M. Hentschel, R. Kienberger, C. Spielmann, G. A. Reider, N. Milosevic, T. Brabec, P. Corkum, U. Heinzmann, M. Drescher, and F. Krausz, "Attosecond metrology," Nature 414, 509-513 (2001).
39. A. Baltuska, M. S. Pshenichnikov, and D. A. Wiersma, "Amplitude and phase characterization of 4.5-fs pulses by frequency-resolved optical gating," Optics Letters 23, 1474-1476 (1998).
40. S. Akturk, C. D'Amico, and A. Mysyrowicz, "Measuring ultrashort pulses in the single-cycle regime using frequency-resolved optical gating," Journal of the Optical Society of America B-Optical Physics 25, A63-A69 (2008).
41. Alphalas, "Response curve of a commercial CCD array," http://www.alphalas.com/products/laser-diagnostic-tools/.
42. L. Gallmann, D. H. Sutter, N. Matuschek, G. Steinmeyer, U. Keller, C. Iaconis, and I. A. Walmsley, "Characterization of sub-6-fs optical pulses with spectral phase interferometry for direct electric-field reconstruction," Optics Letters 24, 1314-1316 (1999).
43. J. R. Birge, and F. X. Kartner, "Analysis and mitigation of systematic errors in spectral shearing interferometry of pulses approaching the single-cycle limit Invited," Journal of the Optical Society of America B-Optical Physics 25, A111-A119 (2008).
44. A. S. Wyatt, I. A. Walmsley, G. Stibenz, and G. Steinmeyer, "Sub-10 fs pulse characterization using spatially encoded arrangement for spectral phase interferometry for direct electric field reconstruction," Optics Letters 31, 1914-1916 (2006).
45. J. R. Birge, H. M. Crespo, and F. X. Kartner, "Theory and design of two-dimensional spectral shearing interferometry for few-cycle pulse measurement," Journal of the Optical Society of America B-Optical Physics 27, 1165-1173 (2010).
46. L. -F. Yang, S. -L. Lin, and S. -D. Yang, "Ultrashort pulse measurements by interferometric spectrogram," Optics Express 18, 6877-6884 (2010).
47. D. N. Nikogosyan, Nonlinear Optical Crystals: A Complete Survey (Springer, 2005).
48. C. -S. Hsu, H. -C. Chiang, H. -P. Chuang, C. -B. Huang, and S. -D. Yang, "Forty-photon-per-pulse spectral phase retrieval by shaper-assisted modified interferometric field autocorrelation," Optics Letters 36, 2611-2613 (2011).
49. G. Taft, A. Rundquist, M. M. Murnane, I. P. Christov, H. C. Kapteyn, K. W. DeLong, D. N. Fittinghoff, M. A. Krumbugel, J. N. Sweetser, and R. Trebino, "Measurement of 10-fs laser pulses," IEEE Journal of Selected Topics in Quantum Electronics 2, 575-585 (1996).
50. R. Morita, M. Hirasawa, N. Karasawa, S. Kusaka, N. Nakagawa, K. Yamane, L. M. Li, A. Suguro, and M. Yamashita, "Sub-5 fs optical pulse characterization," Measurement Science & Technology 13, 1710-1720 (2002).
51. A. M. Weiner, "EFFECT OF GROUP-VELOCITY MISMATCH ON THE MEASUREMENT OF ULTRASHORT OPTICAL PULSES VIA 2ND HARMONIC-GENERATION," Ieee Journal of Quantum Electronics 19, 1276-1283 (1983).
52. P. O'Shea, M. Kimmel, X. Gu, and R. Trebino, "Highly simplified device for ultrashort-pulse measurement," Optics Letters 26, 932-934 (2001).
53. C. Iaconis, and I. A. Walmsley, "Self-referencing spectral interferometry for measuring ultrashort optical pulses," Ieee Journal of Quantum Electronics 35, 501-509 (1999).
54. C. -S. Hsu, Y. -H. Lee, A. Yabushita, T. Kobayashi, and S. -D. Yang, "Spectral phase retrieval of 8 fs optical pulses at 600nm by using a collinear autocorrelator with 300-mu m-thick lithium triborate crystals," Optics Letters 36, 2041-2043 (2011).
55. J. Köhler, M. Wollenhaupt, T. Bayer, C. Sarpe, and T. Baumert, "Zeptosecond precision pulse shaping," Opt. Express 19, 11638-11653 (2011).
56. M. Plewicki, F. Weise, S. M. Weber, and A. Lindinger, "Phase, amplitude, and polarization shaping with a pulse shaper in a Mach-Zehnder interferometer," Applied Optics 45, 8354-8359 (2006).