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CRUZ CD, STEPHENSON JC, ENGMANN S, BITTLE EG, WAHLSTRAND JK. Pump-probe phase spectroscopy with submilliradian sensitivity and nanosecond time delay using Michelson interferometers. OPTICS EXPRESS 2023; 31:14299-14307. [PMID: 37157297 PMCID: PMC11258875 DOI: 10.1364/oe.483358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/15/2023] [Indexed: 05/10/2023]
Abstract
Using two Michelson interferometers, we describe an experimental scheme for sensitive pump-probe spectral interferometry measurements at long time delays. It has practical advantages over the Sagnac interferometer method typically used when long-time delays are required. First, with the Sagnac interferometer, achieving many nanosecond delays requires expanding the size of the interferometer so that the reference pulse arrives before the probe pulse. Because the two pulses still pass through the same region of the sample, long-lived effects can still affect the measurement. In our scheme, the probe and reference pulses are spatially separated at the sample, alleviating the need for a large interferometer. Second, in our scheme, a fixed delay between probe and reference pulses is straightforward to produce and is continuously adjustable while maintaining alignment. Two applications are demonstrated. First, transient phase spectra are presented in a thin tetracene film with up to 5 ns probe delay. Second, impulsive stimulated Raman measurements are presented in Bi4Ge3O12. The signal-to-noise using the double Michelson technique is comparable to previously described methods with the added advantage of arbitrarily long pump-probe time delays.
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Affiliation(s)
- C. D. CRUZ
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - J. C. STEPHENSON
- Associate, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - S. ENGMANN
- Associate, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Theiss Research, La Jolla, CA 92037, USA
| | - E. G. BITTLE
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - J. K. WAHLSTRAND
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
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2
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Patel A, Gollner C, Jutas R, Shumakova V, Shneider MN, Pugzlys A, Baltuska A, Shashurin A. Ionization rate and plasma dynamics at 3.9 micron femtosecond photoionization of air. Phys Rev E 2022; 106:055210. [PMID: 36559482 DOI: 10.1103/physreve.106.055210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/27/2022] [Indexed: 06/17/2023]
Abstract
The introduction of mid-IR optical parametric chirped pulse amplifiers has catalyzed interest in multimillijoule, infrared femtosecond pulse-based filamentation. As tunneling ionization is a fundamental first stage in these high-intensity laser-matter interactions, characterizing the process is critical to understand derivative topical studies on femtosecond filamentation and self-focusing. Here, we report direct nonintrusive measurements of total electron count and electron number densities generated at 3.9 μm femtosecond midinfrared tunneling ionization of atmospheric air using constructive-elastic microwave scattering. Subsequently, we determine photoionization rates to be in the range 5.0×10^{8}-6.1×10^{9}s^{-1} for radiation intensities of 1.3×10^{13}-1.9×10^{14}W/cm^{2}, respectively. The proposed approach paves the wave to precisely tabulate photoionization rates in mid-IR for a broad range of intensities and gas types and to study plasma dynamics at mid-IR filamentation.
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Affiliation(s)
- Adam Patel
- School of Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907, USA
| | - Claudia Gollner
- Photonics Institute, Vienna University of Technology, 1040 Vienna, Austria
| | - Rokas Jutas
- Photonics Institute, Vienna University of Technology, 1040 Vienna, Austria
| | | | - Mikhail N Shneider
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Audrius Pugzlys
- Photonics Institute, Vienna University of Technology, 1040 Vienna, Austria
| | - Andrius Baltuska
- Photonics Institute, Vienna University of Technology, 1040 Vienna, Austria
| | - Alexey Shashurin
- School of Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907, USA
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3
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Nie Z, Nambu N, Marsh KA, Welch E, Matteo D, Zhang C, Wu Y, Patchkovskii S, Morales F, Smirnova O, Joshi C. Cross-polarized common-path temporal interferometry for high-sensitivity strong-field ionization measurements. OPTICS EXPRESS 2022; 30:25696-25706. [PMID: 36237094 DOI: 10.1364/oe.463424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 06/17/2022] [Indexed: 06/16/2023]
Abstract
Absolute density measurements of low-ionization-degree or low-density plasmas ionized by lasers are very important for understanding strong-field physics, atmospheric propagation of intense laser pulses, Lidar etc. A cross-polarized common-path temporal interferometer using balanced detection was developed for measuring plasma density with a sensitivity of ∼0.6 mrad, equivalent to a plasma density-length product of ∼2.6 × 1013 cm-2 if using an 800 nm probe laser. By using this interferometer, we have investigated strong-field ionization yield versus intensity for various noble gases (Ar, Kr, and Xe) using 800 nm, 55 fs laser pulses with both linear (LP) and circular (CP) polarization. The experimental results were compared to the theoretical models of Ammosov-Delone-Krainov (ADK) and Perelomov-Popov-Terent'ev (PPT). We find that the measured phase change induced by plasma formation can be explained by the ADK theory in the adiabatic tunneling ionization regime, while PPT model can be applied to all different regimes. We have also measured the photoionization and fractional photodissociation of molecular (MO) hydrogen. By comparing our experimental results with PPT and MO-PPT models, we have determined the likely ionization pathways when using three different pump laser wavelengths of 800 nm, 400 nm, and 267 nm.
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Hancock SW, Zahedpour S, Milchberg HM. Transient-grating single-shot supercontinuum spectral interferometry (TG-SSSI). OPTICS LETTERS 2021; 46:1013-1016. [PMID: 33649642 DOI: 10.1364/ol.417803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
We present a technique for the single-shot measurement of the spatiotemporal (1D space+time) amplitude and phase of an ultrashort laser pulse. The method, transient grating single-shot supercontinuum spectral interferometry (TG-SSSI), is demonstrated by the space-time imaging of short pulses carrying spatiotemporal optical vortices. TG-SSSI is well suited for characterizing ultrashort laser pulses that contain singularities associated with spin/orbital angular momentum or polarization.
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Fedorov VY, Tzortzakis S. Powerful terahertz waves from long-wavelength infrared laser filaments. LIGHT, SCIENCE & APPLICATIONS 2020; 9:186. [PMID: 33298833 PMCID: PMC7665013 DOI: 10.1038/s41377-020-00423-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 10/11/2020] [Accepted: 10/19/2020] [Indexed: 06/02/2023]
Abstract
Strong terahertz (THz) electric and magnetic transients open up new horizons in science and applications. We review the most promising way of achieving sub-cycle THz pulses with extreme field strengths. During the nonlinear propagation of two-color mid-infrared and far-infrared ultrashort laser pulses, long, and thick plasma strings are produced, where strong photocurrents result in intense THz transients. The corresponding THz electric and magnetic field strengths can potentially reach the gigavolt per centimeter and kilotesla levels, respectively. The intensities of these THz fields enable extreme nonlinear optics and relativistic physics. We offer a comprehensive review, starting from the microscopic physical processes of light-matter interactions with mid-infrared and far-infrared ultrashort laser pulses, the theoretical and numerical advances in the nonlinear propagation of these laser fields, and the most important experimental demonstrations to date.
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Affiliation(s)
- Vladimir Yu Fedorov
- Science Program, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar.
- P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 53 Leninskiy Prospekt, Moscow, 119991, Russia.
| | - Stelios Tzortzakis
- Science Program, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar.
- Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), P.O. Box 1527, Heraklion, GR-71110, Greece.
- Department of Materials Science and Technology, University of Crete, Heraklion, GR-71003, Greece.
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Tolliver J, Zahedpour S, Wahlstrand JK, Milchberg HM, Kolesik M. Nonlinearity and ionization in Xe: experiment-based calibration of a numerical model. OPTICS LETTERS 2020; 45:5780-5783. [PMID: 33057283 PMCID: PMC8218235 DOI: 10.1364/ol.408403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
Recently proposed universality of the nonlinear response is put to the test and used to improve a previously designed model for xenon. Utilizing accurate measurements resolving the nonlinear polarization and ionization in time and space, we calibrate the scaling parameters of the model and demonstrate agreement with several experiments spanning the intensity range relevant for applications in nonlinear optics at near-infrared and mid-infrared wavelengths. Applications to other species including small molecules are discussed, suggesting a self-consistent way to calibrate light-matter interaction models.
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Affiliation(s)
- J. Tolliver
- College of Optical Sciences, University of Arizona, Tucson, Arizona 85712, USA
| | - S. Zahedpour
- Institute for Research in Electronics & Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - J. K. Wahlstrand
- Institute for Research in Electronics & Applied Physics, University of Maryland, College Park, Maryland 20742, USA
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - H. M. Milchberg
- Institute for Research in Electronics & Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - M. Kolesik
- College of Optical Sciences, University of Arizona, Tucson, Arizona 85712, USA
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Heinz J, Reiff R, Joyce T, Becker A, Jaroń-Becker A, Kolesik M. Nonlinear polarization and ionization in O 2: metastable electronic state model. OPTICS EXPRESS 2020; 28:25022-25036. [PMID: 32907033 DOI: 10.1364/oe.399719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 08/04/2020] [Indexed: 06/11/2023]
Abstract
We present a computational model for the nonlinear response of molecular oxygen exposed to strong mid-wavelength and long-wavelength infrared optical fields. Based on a non-Hermitian approach utilizing metastable electronic states, the nonlinear polarization and strong-field ionization are described as intimately connected properties. Good agreement with the measured nonlinear index and ionization rates is shown, and parameterized response functions are provided to facilitate applications in large-scale simulations of infrared optical pulses interacting with gaseous media.
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Larkin I, Griff-McMahon J, Schweinsberg A, Goffin A, Valenzuela A, Milchberg HM. Full path single-shot imaging of femtosecond pulse collapse in air turbulence. OPTICS LETTERS 2020; 45:2518-2521. [PMID: 32356805 DOI: 10.1364/ol.389495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/23/2020] [Indexed: 06/11/2023]
Abstract
In a single shot, we measure the full propagation path, including the evolution to pulse collapse, of a high power femtosecond laser pulse propagating in air. Our technique enables examination of the effect of parameters that fluctuate on a shot-to-shot basis, such as pulse energy, pulse duration, and air turbulence-induced refractive index perturbations. We find that even in lab air over relatively short propagation distances, turbulence plays a significant role in determining the location of pulse collapse.
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Patel D, Jang D, Hancock SW, Milchberg HM, Kim KY. Simplified single-shot supercontinuum spectral interferometry. OPTICS EXPRESS 2020; 28:11023-11032. [PMID: 32403622 DOI: 10.1364/oe.386631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 03/20/2020] [Indexed: 06/11/2023]
Abstract
We have experimentally demonstrated a simplified method for performing single-shot supercontinuum spectral interferometry (SSSI) that does not require pre-characterization of the probe pulse. The method, originally proposed by D. T. Vu, D. Jang, and K. Y. Kim, uses a genetic algorithm (GA) and as few as two time-delayed pump-probe shots to retrieve the pump-induced phase shift on the probe [Opt. Express26, 20572 (2018)]. We show that the GA is able to successfully retrieve the transient modulations on the probe, and that the error in the retrieved modulation decreases dramatically with the number of shots used. In addition, we propose and demonstrate a practical method that allows SSSI to be done with a single pump-probe shot (again, without the need for pre-characterization of the probe). This simplified method can prove to be immensely useful when performing SSSI with a low-repetition-rate laser source.
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Woodbury D, Schwartz RM, Rockafellow E, Wahlstrand JK, Milchberg HM. Absolute Measurement of Laser Ionization Yield in Atmospheric Pressure Range Gases over 14 Decades. PHYSICAL REVIEW LETTERS 2020; 124:013201. [PMID: 31976702 DOI: 10.1103/physrevlett.124.013201] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Indexed: 06/10/2023]
Abstract
Strong-field ionization is central to intense laser-matter interactions. However, standard ionization measurements have been limited to extremely low density gas samples, ignoring potential high density effects. Here, we measure strong-field ionization in atmospheric pressure range air, N_{2}, and Ar over 14 decades of absolute yield, using mid-IR picosecond avalanche multiplication of single electrons. Our results are consistent with theoretical rates for isolated atoms and molecules and quantify the ubiquitous presence of ultralow concentration gas contaminants that can significantly affect laser-gas interactions.
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Affiliation(s)
- D Woodbury
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - R M Schwartz
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - E Rockafellow
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
| | - J K Wahlstrand
- Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - H M Milchberg
- Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742, USA
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Panagiotopoulos P, Kolesik M, Tochitsky S, Koch SW, Moloney JV. Two-stage filamentation of 10 μm pulses as a broadband infrared backlighter in the atmosphere. OPTICS LETTERS 2019; 44:3122-3125. [PMID: 31199396 DOI: 10.1364/ol.44.003122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/23/2019] [Indexed: 06/09/2023]
Abstract
We identify a two-stage filamentation regime for high-power 10 μm multipicosecond pulses propagating in the atmosphere. The first low-intensity stage is mainly regularized by ionization through excitation induced dephasing, which can lead to strong pulse shortening downstream. This shortening in turn causes a significant reduction of the many-body induced plasma, which changes the dynamics drastically. As a result, a distinct second stage is predicted where peak intensities are clamped at 1 order of magnitude higher than in the first stage. The complex dynamics found in the second stage can result in the spatial and temporal breakup of the wavepacket, reduction of ionization losses, and extreme spectral broadening.
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12
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Tolliver J, Kolesik M. True versus effective Kerr nonlinear response in optical filamentation. OPTICS EXPRESS 2018; 26:30172-30182. [PMID: 30469895 DOI: 10.1364/oe.26.030172] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 10/13/2018] [Indexed: 06/09/2023]
Abstract
The optical Kerr effect, and the nonlinear polarization in general, represents an important light-matter interaction governing many regimes encountered in the nonlinear optics. We reason that in the context of optical filamentation one should distinguish the third-order Kerr effect occurring at relatively low light intensities from the effective Kerr nonlinearity relevant to higher intensity. While many properties of filaments can be captured well with a third-order nonlinear polarization model with a nonlinear index chosen somewhat higher than the true nonlinear index operative at low intensities, our comparative simulations indicate that some filamentation aspects carry significant signatures from the higher-order nonlinearity.
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