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Liang SP, Lu IC, Tsai ST, Chen JL, Lee YT, Ni CK. Laser Pulse Width Dependence and Ionization Mechanism of Matrix-Assisted Laser Desorption/Ionization. J Am Soc Mass Spectrom 2017; 28:2235-2245. [PMID: 28707193 DOI: 10.1007/s13361-017-1734-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 01/24/2017] [Accepted: 06/05/2017] [Indexed: 06/07/2023]
Abstract
Ultraviolet laser pulses at 355 nm with variable pulse widths in the region from 170 ps to 1.5 ns were used to investigate the ionization mechanism of matrix-assisted laser desorption/ionization (MALDI) for matrices 2,5-dihydroxybenzoic acid (DHB), α-cyano-4-hydroxycinnamic acid (CHCA), and sinapinic acid (SA). The mass spectra of desorbed ions and the intensity and velocity distribution of desorbed neutrals were measured simultaneously for each laser shot. These quantities were found to be independent of the laser pulse width. A comparison of the experimental measurements and numerical simulations according to the multiphoton ionization, coupled photophysical and chemical dynamics (CPCD), and thermally induced proton transfer models showed that the predictions of thermally induced proton transfer model were in agreement with the experimental data, but those of the multiphoton ionization model were not. Moreover, the predictions of the CPCD model based on singlet-singlet energy pooling were inconsistent with the experimental data of CHCA and SA, but were consistent with the experimental data of DHB only when some parameters used in the model were adjusted to extreme values. Graphical Abstract ᅟ.
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Affiliation(s)
- Sheng-Ping Liang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
| | - I-Chung Lu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
- Department of Chemistry, Wayne State University, Detroit, MI, 48202, USA
| | - Shang-Ting Tsai
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
| | - Jien-Lian Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
| | - Yuan Tseh Lee
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Chi-Kung Ni
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan.
- Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan.
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Chen WJ, Hsieh ZM, Huang SW, Su HY, Lai CJ, Tang TT, Lin CH, Lee CK, Pan RP, Pan CL, Kung AH. Sub-single-cycle optical pulse train with constant carrier envelope phase. Phys Rev Lett 2008; 100:163906. [PMID: 18518202 DOI: 10.1103/physrevlett.100.163906] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Indexed: 05/26/2023]
Abstract
We describe the synthesis of periodic waveforms consisting of a train of pulses that are 0.83 cycles long and have an electric field pulse width of 0.44 fs using 7 Raman sidebands generated by molecular modulation in H2. We verify by optical correlation that the carrier-envelope phase is constant in these waveforms when they are synthesized from commensurate sidebands. The estimated overall shift of the carrier-envelope phase is less than 0.18 cycles from the first to the last pulse of nearly 10(6) pulses in the pulse train.
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Affiliation(s)
- Wei-Jan Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
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Dupré P, Miller TA. Quasi-Fourier-transform limited, scannable, high energy titanium-sapphire laser source for high resolution spectroscopy. Rev Sci Instrum 2007; 78:033102. [PMID: 17411173 DOI: 10.1063/1.2670804] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A tunable injection seeded Ti:sapphire laser source has been developed and tested. Slave-master tandem cavity and ramp-lock-and-fire concepts have been implemented and fully controlled by a digital signal processor. A Fourier-transform-based analysis, as well as direct measurements, have demonstrated spectral linewidths in the range of 3.5-15 MHz (HWHM), with potential tunability over the entire Ti:sapphire lasing range. A quasi-Fourier-transform limited spectral linewidth is demonstrated assuming a secant hyperbolic shape of the electromagnetic field. Output energies >100 mJ have been reached with approximately 300 mJ of pump energy. The highest spectral purity is obtained using the quadruple pumping scheme.
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Affiliation(s)
- Patrick Dupré
- Laser Spectroscopy Facility, Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210, USA.
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Zhang G, Chen KS, Merer AJ, Hsu YC, Chen WJ, Shaji S, Liao YA. The 4051-Angstroms band of C3 (A 1Piu-X 1Sigmag +, 000-000): perturbed low-J lines and lifetime measurements. J Chem Phys 2007; 122:244308. [PMID: 16035758 DOI: 10.1063/1.1928827] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Rotational analyses have been carried out at high resolution for the 000-000 and 000-100 bands of the A (1)Pi(u)-X (1)Sigma(g) (+) transition of supersonic jet-cooled C(3). Two different spectra have been recorded for each band, using time gatings of 20-150 and 800-2300 ns. At the shorter time delay the spectra show only the lines observed by many previous workers. At the longer time delay many extra lines appear, some of which have been observed previously by [McCall et al.Chem. Phys. Lett. 374, 583 (2003)] in cavity ring-down spectra of jet-cooled C(3). Detailed analysis of these extra lines shows that at least two long-lived states perturb the A (1)Pi(u), 000 state. One of these appears to be a (3)Sigma(u) (-) vibronic state, which may possibly be a high vibrational level of the b (3)Pi(g) state, and the other appears to be a P = 1 state with a low rotational constant B. Our spectra also confirm the reassignment by McCall et al. of the R(0) line of the 000-000 band, which is consistent with the spectra recorded towards a number of stars that indicate the presence of C(3) in the interstellar medium. Fluorescence lifetimes have been measured for a number of upper-state rotational levels. The rotational levels of the A (1)Pi(u) state have lifetimes in the range of 230-190 ns, decreasing slightly with J; the levels of the perturbing states have much longer lifetimes, with some of them showing biexponential decays. An improved value has been obtained for the nu(1) vibrational frequency of the ground state, nu(1) = 1224.4933 +/- 0.0029 cm(-1).
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Affiliation(s)
- Guiqiu Zhang
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
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Chen WJ, Kung AH. Tunable deep-ultraviolet source generated by scattering off adiabatically prepared Raman coherence in hydrogen gas. Opt Lett 2005; 30:2608-10. [PMID: 16208915 DOI: 10.1364/ol.30.002608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We demonstrate a tunable deep-ultraviolet coherent source generated by the beating of a tunable UV laser and strongly driven vibrational Raman coherence in hydrogen. The total energy conversion efficiency reaches a maximum of 50% at the phase side of the Raman coherence. The generated spectrum of Raman sidebands tunes with the input and extends from 435 to 146 nm for an input at 282 nm.
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Affiliation(s)
- Wei-Jan Chen
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
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Tsai ST, Jiang JC, Lin MF, Lee YT, Ni CK. Carbon–carbon bond cleavage in the photoionization of ethanol and 1-propanol clusters. J Chem Phys 2004; 120:8979-84. [PMID: 15267833 DOI: 10.1063/1.1704637] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Tunable VUV laser was used to initiate the ion-molecule reactions in the clusters of ethanol and 1-propanol by photoionization in the region between 10.49 to 10.08 eV. Ionic products were detected by the time-of-flight mass spectrometer. In addition to the protonated clusters from proton transfer reactions, the products corresponding to beta carbon-carbon bond cleavage were found to be one of the major products for small sizes of clusters. A comparison with photoionization of methanol clusters and the results of ab initio calculation has been made.
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Affiliation(s)
- Shang-Ting Tsai
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei, 106, Taiwan, Republic of China
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Abstract
We report on a 1-W injection-locked cw titanium:sapphire ring laser at 846 nm. Single-frequency operation requires only a few milliwatts of injected power. This relatively simple and inexpensive system can be used for watt-level single-frequency lasers across most of the titanium:sapphire gain region. A brief review of injection-locking theory is given, and conclusions based on this theory indicate ways to improve the performance of the system.
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Affiliation(s)
- Elizabeth A Cummings
- Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602-4640, USA
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Stoykova EV, Nenchev MN. Fizeau wedge with unequal mirrors for spectral control and coupling in a linear laser oscillator-amplifier system. Appl Opt 2001; 40:5402-5412. [PMID: 18364820 DOI: 10.1364/ao.40.005402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We propose a new tunable linear laser oscillator-amplifier system that incorporates a Fizeau wedge with unequal mirrors as the coupler. Because of asymmetry in reflection and wedge focusing in unequal mirrors, our system acts as a highly efficient selector in the oscillator and practically eliminates reinjection of spontaneous emission in the amplifier. We studied the wedge action by developing a procedure for the calculation of reflected interference patterns at a distance from the wedge. Using this procedure we found the feedback factors for both the oscillator and the amplifier. Background emission levels of less than 1% of the peak intensity in the emitted line were experimentally obtained.
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Chou YC, Huang CL, Chen IC, Ni CK, Kung AH. Rotationally resolved spectra of transitions involving motion of the methyl group of acetaldehyde in the system à 1A″−X̃ 1A′. J Chem Phys 2001. [DOI: 10.1063/1.1394751] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Huang CL, Chen IC, Merer AJ, Ni CK, Kung AH. Spectra of jet-cooled 32SO2 and 34SO2 in systems ã 3B1 and b̃ 3A2–X̃ 1A1: Rotational structure of perturbed b̃ 3A2. J Chem Phys 2001. [DOI: 10.1063/1.1333019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Huang CL, Ju SS, Chen IC, Merer AJ, Ni CK, Kung AH. High-Resolution Spectroscopy of Jet-Cooled (32)SO(2) and (34)SO(2): The ã(3)B(1)-;X(1)A(1), 2(1)(0) and 1(1)(0) Bands. J Mol Spectrosc 2000; 203:151-157. [PMID: 10930343 DOI: 10.1006/jmsp.2000.8151] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Laser-induced excitation spectra of the two bands ã(3)B(1)-;X(1)A(1), 2(1)(0) and 1(1)(0) of (32)SO(2) and (34)SO(2) have been recorded in a supersonic jet at a resolution of 0.015 cm(-1). The rotational and electron-spin fine structure has been analyzed for both isotopic species. Analysis of the rotational and electron-spin fine structure yields precise values of the rotational constants A, B, and C and the spin constants alpha and beta for both (32)SO(2) and (34)SO(2) in the states ã(3)B(1) (010) and (100). No interaction between these two vibrational states with any nearby triplet state is observed for rotational levels with J </= 8 and K </= 2. Copyright 2000 Academic Press.
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Affiliation(s)
- CL Huang
- Department of Chemistry, National Tsing Hua University, Hsinchu, 300, Taiwan
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Huang CL, Chien V, Ni CK, Kung AH, Chen IC. State-Resolved Dynamics of Dissociation of Triplet Acetaldehyde: Rate of Appearance of Fragment HCO and Decay of Excited States of Parent Molecule. J Phys Chem A 2000. [DOI: 10.1021/jp000478p] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Cheng-Liang Huang
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 300, Republic of China, and Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei, Taiwan 106, Republic of China
| | - Volume Chien
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 300, Republic of China, and Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei, Taiwan 106, Republic of China
| | - Chi-Kung Ni
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 300, Republic of China, and Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei, Taiwan 106, Republic of China
| | - A. H. Kung
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 300, Republic of China, and Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei, Taiwan 106, Republic of China
| | - I-Chia Chen
- Department of Chemistry, National Tsing Hua University, Hsinchu, Taiwan 300, Republic of China, and Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei, Taiwan 106, Republic of China
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Huang CL, Chien V, Chen IC, Ni CK, Kung AH. State-resolved dissociation dynamics of triplet acetaldehyde near the dissociation threshold to form CH3+HCO. J Chem Phys 2000. [DOI: 10.1063/1.480742] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Tsai ST, Jiang JC, Lee YT, Kung AH, Lin SH, Ni CK. Photoionization of methanol dimer using a tunable vacuum ultraviolet laser. J Chem Phys 1999. [DOI: 10.1063/1.479628] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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