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Kudryashov SI, Danilov PA, Kuzmin EV, Gulina YS, Rupasov AE, Krasin GK, Zubarev IG, Levchenko AO, Kovalev MS, Pakholchuk PP, Ostrikov SA, Ionin AA. Pulse-width-dependent critical power for self-focusing of ultrashort laser pulses in bulk dielectrics. OPTICS LETTERS 2022; 47:3487-3490. [PMID: 35838709 DOI: 10.1364/ol.462693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Microscale filamentation of 0.25 NA-focused, linearly and circularly polarized 1030 nm and 515 nm ultrashort laser pulses of variable pulse widths in fused silica, fluorite, and natural and synthetic diamonds demonstrates the Raman-Kerr effect in the form of critical pulse power magnitudes, proportional to squared wavelength and inversely proportional to laser pulse width of 0.3-10 ps. The first trend represents the common spectral relationship between the quantities, while the second indicates its time-integrated inertial contribution of Raman-active lattice polarization, appearing in transmission spectra via ultrafast optical-phonon Raman scattering. The optical-phonon contribution to the nonlinear polarization could come from laser field-induced spontaneous/stimulated Raman scattering and coherent optical phonons generated by electron-hole plasma with its clamped density in the nonlinear focus. Almost constant product value of the (sub)picosecond laser pulse widths and corresponding critical pulse powers for self-focusing and filamentation in the dielectrics ("critical pulse energy") apparently implies constant magnitude of the nonlinear polarization and other "clamped" filamentation parameters at the given wavelength.
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Yu J, Han Y, Zhang H, Misochko OV, Nakamura KG, Hu J. Attosecond-Resolved Coherent Control of Lattice Vibrations in Thermoelectric SnSe. J Phys Chem Lett 2022; 13:2584-2590. [PMID: 35289629 DOI: 10.1021/acs.jpclett.2c00426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Manipulating lattice vibrations is the cornerstone to achieving ultralow thermal conductivity in thermoelectrics. Although spatial control by novel material designs has been recently reported, temporal manipulation, which can shape thermoelectric properties under nonequilibrium conditions, remains largely unexplored. Here, taking SnSe as a representative, we have demonstrated that in the ultrafast pump-pump-probe spectroscopy, electronic and lattice coherences inherited from optical excitations can be exploited independently to manipulate phonon oscillations in a highly selective manner. Specifically, when the pump-pump delay time (tmod) is in the electronic coherence time range, the amplitude, frequency, and lifetime of all phonon modes are simultaneously following the optical cycle. While extending tmod into the lattice coherence time range, the amplitude of each coherent phonon mode can be selectively manipulated according to its intrinsic period without changing the frequency and lifetime. This work opens up exciting avenues to temporally and discriminatorily manipulate phononic processes in thermoelectric materials.
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Affiliation(s)
- Junhong Yu
- Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China
| | - Yadong Han
- Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China
- State Key Laboratory for Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China
| | - Hang Zhang
- Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China
- State Key Laboratory for Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China
| | - Oleg V Misochko
- State Key Laboratory for Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China
- Institute of Solid State Physics, Russian Academy of Sciences, 142432 Chernogolovka, Moscow Region, Russia
| | - Kazutaka G Nakamura
- Materials and Structures Laboratory, Tokyo Institute of Technology, R3-10, 4259 Nagatsuta, Yokohama 226-8503, Japan
| | - Jianbo Hu
- Laboratory for Shock Wave and Detonation Physics, Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900, China
- State Key Laboratory for Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China
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Iwai S, Kawakami Y, Itoh H, Yonemitsu K. Petahertz charge dynamics in a correlated organic superconductor. Faraday Discuss 2022; 237:353-367. [DOI: 10.1039/d2fd00004k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report an observation of stimulated emission induced by a nearly single-cycle 6 fs near infrared electric field of 10 MV/cm in an organic superconductor (κ-(h-ET)2Cu[N(CN)2]Br). The stimulated emission is...
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Motojima M, Suzuki T, Shigekawa H, Kainuma Y, An T, Hase M. Giant nonlinear optical effects induced by nitrogen-vacancy centers in diamond crystals. OPTICS EXPRESS 2019; 27:32217-32227. [PMID: 31684438 DOI: 10.1364/oe.27.032217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 10/07/2019] [Indexed: 06/10/2023]
Abstract
We investigate the effect of nitrogen-vacancy (NV) centers in single crystal diamond on nonlinear optical effects using 40 fs femtosecond laser pulses. The near-infrared femtosecond pulses allow us to study purely nonlinear optical effects, such as optical Kerr effect (OKE) and two-photon absorption (TPA), related to unique optical transitions by electronic structures with NV centers. It is found that both nonlinear optical effects are enhanced by the introduction of NV centers in the N + dose levels of 2.0×10 11 and 1.0×10 12 N +/cm 2. In particular, our data demonstrate that the OKE signal is strongly enhanced for the heavily implanted type-IIa diamond. We suggest that the strong enhancement of the OKE is possibly originated from cascading OKE, where the high-density NV centers effectively break the inversion symmetry near the surface region of diamond.
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Yano K, Katsuki H, Yanagi H. Mode selective excitation of terahertz vibrations in single crystalline rubrene. J Chem Phys 2019; 150:054503. [PMID: 30736674 DOI: 10.1063/1.5068732] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Organic molecular crystals have a variety of low frequency vibrational modes composed of intra- and inter-molecular oscillations. They are mixed intricately in the terahertz (THz) region. We are interested in the controllability of the vibrational energy distribution among such THz vibrational modes based on the femtosecond double-pulse excitation scheme. Single crystalline rubrene is prepared by physical vapor transport. The optical response of vibrational modes in the electric ground state of rubrene is detected by the ultrafast pump-probe reflectivity measurement at 90 K. Three oscillation modes at 3.20, 3.67, and 4.18 THz are detected, and we demonstrate selective enhancement and depletion of each mode by properly tuning the double-pulse delay. The amplitude of the selected vibrational mode is modulated between 0.149 and 1.87, where 1.0 corresponds to the amplitude excited with a single pump pulse. The double-pulse delay dependence of the observed vibrational amplitude is simulated based on the classical driven harmonic oscillator model, and the results reasonably reproduce our experimental signals. Such selective manipulation of the vibrational amplitude can be a potential tool to investigate the vibronic and electron-phonon couplings which plays an important role for the charge transport characteristics and various optoelectronic properties in organic molecular crystals.
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Affiliation(s)
- Keisuke Yano
- Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, Japan
| | - Hiroyuki Katsuki
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, Japan
| | - Hisao Yanagi
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara, Japan
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