145) Y. Cho, F. Shafiei, B. S. Mendoza, M. Lei, T. Jiang, P. S. Ho and M. C. DOWNER, “Second-harmonic microscopy of strain fields around through-silicon-vias,” Appl. Phys. Lett. 108, 151602 (2016). 

144) B. S. Mendoza, Y. Cho, F. Shafiei, and M. C. DOWNER, “Surface second-harmonic generation induced by 3D strain fields,” Phys. Stat. Sol. B 253, 218-225 (2016). 

143) A. S. Ramm, N. Sakib, A. Bhasin and M. C. DOWNER, “Optical characterization of temperature- and composition-dependent microstructure in asphalt binders,” J. Microscopy 262 (3), 216-225 (2015). 

142) H.-E. Tsai, X. Wang, J. M. Shaw, Z. Li, A. V. Arefiev, X. Zhang, R. Zgadzaj, W. Henderson, V. Khudik, G.
Shvets, and M. C. DOWNER, "Compact tunable Compton x-ray source from laser-plasma accelerator and
plasma mirror," Physics of Plasmas 22, 023106 (2015).

141) Mike Downer and Rafal Zgadzaj, "Surf's up at SLAC," Nature (London) 515, 40 (2014).

140) Zhengyan Li, Hai-En Tsai, X. Zhang, C.-H. Pai, R. Zgadzaj, X. Wang, V. Khudik, G. Shvets and M. C.
DOWNER, "Single-shot optical visualization of evolving laser wakefields using an all-optical streak camera,"
Physical Review Letters 113, 085001 (2014).

139) Zhengyan Li, R. Zgadzaj, X. Wang, Y. Y. Chang, and M. C. DOWNER, “Single-shot tomographic movies of evolving light-velocity objects,” Nature Communications 5, 3085 (2014).

138) Zhengyan Li, Y. Y. Chang and M. C. DOWNER, “Single-shot imaging of evolving light-velocity objects by multi-object-plane phase-contrast imaging,” Optics Letters 38, 5157 (2013).

137) X. Gao, A. V. Arefiev, R. C. Korzekwa, X. Wang, B. Shim, M. C. DOWNER, “Spatio-temporal profiling of cluster mass fraction in a pulsed supersonic gas jet by frequency-domain holography,” J. Appl. Phys. 114, 034903 (2013).

136) X. Wang, R. Zgadzaj, N. Fazel, Z. Li, S. A. Yi, X. Zhang, W. Henderson, Y. –Y. Chang, R. Korzekwa, H.-E. Tsai, C.-H. Pai, H. Quevedo, G. Dyer, E. Gaul, M. Martinez, A. C. Bernstein, T. Borger, M. Spinks, M. Donovan, V. Khudik, G. Shvets, T. Ditmire and M. C. DOWNER, “Quasi-monoenergetic laser-plasma acceleration of electrons to 2 GeV,” Nature Communications 4, 1988 (2013).

135) Y.An, J. Price, Ming Lei and M. C. DOWNER, "Role of photo-assisted tunneling in time-dependent second-harmonic generation from Si surfaces with ultrathin oxides," Appl. Phys. Lett. 102, 051602 (2013).

134) Ming Lei, J. Price, Wei-e Wang, Man Hoi Wong, G. Bersuker and M. C. DOWNER, “Characterization of anti-phase boundaries in hetero-epitaxial polar-on-nonpolar semiconductor films by optical second-harmonic generation,” Appl. Phys. Lett. 102, 152103 (2013).

133) B. S. Mendoza, J. Wei and M. C. DOWNER, “Blue-shift of E₂ critical point resonance in optical second-harmonic spectrum of Si nanocrystals,” physica status solidi (b) 249, 1166-1172 (2012).

132) Ming Lei, J. H. Yum, S. K. Banerjee and M. C. DOWNER, “Band offsets of atomic layer deposited Al₂O₃ and HfO₂ on Si measured by linear and nonlinear photoemission,” physica status solidi (b) 249, 1160-1165 (2012).

131) J.H. Yum, T. Akyol, M. Lei, D.A. Ferrer, Todd.W. Hudnall, M. DOWNER, C.W. Bielawski, G. Bersuker, J.C. Lee, S.K. Banerjee, “Electrical and physical characteristics for crystalline atomic layer deposited beryllium oxide thin film on Si and GaAs substrates,” Thin Solid Films 520, 3091-3095 (2012).

130) C. Hessel, J. Wei, D. Reid, H. Fujii, M. C. DOWNER and B. Korgel, “Raman spectroscopy of oxide-embedded and ligand-stabilized silicon nanocrystals,” J. Phys. Chem. Lett. 3, 1089-1093 (2012).

129) X. Wang, R. Zgadzaj, A. S. Yi, V. Khudik, W. Henderson, N. Fazel, Y. Y. Chang, R. Korzekwa, H.-E. Tsai, C.-H. PAI, Z. Li, E. Gaul, M. Martinez, G. Dyer, H. Quevdedo, A. Bernstein, M. Donovan, G. Shvets, T. Ditmire and M. C. DOWNER, “Self-injected petawatt laser-driven plasma electron acceleration in 10¹⁷ cm^-3 plasma,” J. Plasma Phys. 78, 413-419 (2012).

128) Ming Lei, J. H. Yum, J. Price, Todd W. Hudnall, C. W. Bielawski, S. K. Banerjee, P. S. Lysaght, G. Bersuker, and M. C. Downer, "Spectroscopic evaluation of band alignment of atomic layer deposited BeO on Si(100)," Appl. Phys. Lett. 100, 122906 (2012).

127) X. Gao, X. Wang, B. Shim, A. V. Arefiev, R. Korzekwa, and M. C. Downer, "Characterization of cluster/monomer ratio in pulsed supersonic gas jets," Appl. Phys. Lett. 100, 064101 (2012).

126) J. H. Yum, T. Akyol, M. Lei, D. A. Ferrer, T. W. Hudnall, M. C. DOWNER, C. W. Bielawski, G. Bersuker, J. C. Lee and S. K. Banerjee, “Inversion type InP metal-oxide-semiconductor field effect transistor using novel atomic layer deposited BeO gate dielectric,” Appl. Phys. Lett. 99, 033502 (2011).

125) J. H. Yum, T. Akyol, D. A. Ferrer, J. C. Lee, S. K. Banerjee, M. Lei, M. C. DOWNER, T. W. Hudnall, C. W. Bielawski and G. Bersuker, “Comparison of the self-cleaning effects and electrical characteristics of BeO and Al₂O₃ deposited as an interface passivation layer on GaAs MOS device,” J. Vac. Sci. Technol. A 29, 061501 (2011).

124) J. H. Yum, G. Berusker, T. Akyol, D. A. Ferrer, M. Lei, K. W. Park, T. W. Hudnall, M. C. DOWNER, C. W. Bielawski, E. T. Yu, J. Price, J. C. Lee and S.K. Banerjee, “Epitaxial ALD BeO: Efficient oxygen diffusion barrier for EOT scaling and reliability improvement,” IEEE Trans. Electron. Devices 58, 4384-4392 (2011).

123) J. H. Yum, T. Akyol, M. Lei, T. Hudnall, G. Bersuker, M. C. DOWNER, C. W. Bielawski, J. C. Lee and S. K. Banerjee, “Atomic-layer-deposited beryllium oxide: effective passivation layer for III-V metal/oxide/semiconductor devices,” J. Appl. Phys. 109, 064101 (2011).

122) S. Y. Kalmykov, A. Beck, S. A. Yi, V. N. Khudik, M. C. DOWNER, E. Lefebvre, B. A. Shadwick, and D. P. Umstadter, “Electron self-injection into an evolving plasma bubble: Quasi-monoenergetic laser-plasma acceleration in the blowout regime,” Phys. Plasmas 18, 056704 (2011).

121) J. Wei, A. Wirth, M. C. Downer and B. S. Mendoza, “Second-harmonic and linear optical spectroscopic study of Si nanocrystals embedded in SiO₂,” Phys. Rev. B 84, 165316 (2011).

120) J. Wei, J. Price, T. Wang, C. Hessel and M.C. Downer, “Size-dependent optical properties of Si nanocrystals embedded in amorphous SiO₂ measured by spectroscopic ellipsometry,” J. Vac. Sci. Technol. B 29, 04D112 (2011).

119) T. Wang, J. Wei, M. C. Downer, and J. G. Ekerdt, “Optical Properties of La-Incorporated HfO₂ upon Crystallization,” Appl. Phys. Lett. 98, 122904 (2011).

118) Z. Li, R. Zgadzaj, X. Wang, S. Reed and M. C. DOWNER, “Frequency-domain streak camera for ultrafast imaging of evolving light-velocity objects,” Optics Letters 35, 4087-4089 (2010).

117) A. Arefiev, B. Breizman, V. Khudik, X. Wang and M. C. DOWNER, “Generation of fast ions by microclusters,” Plasma and Fusion Research 5, S2071 (2010).

116) Ming Lei, J. Price, and M. C. Downer, "Hot carrier injection from nanometer-thick silicon-on-insulator films measured by optical second-harmonic generation," Appl. Phys. Lett. 96, 241105 (2010); doi:10.1063/1.3455317.

115) J. Price, Ming Lei, P. S. Lysaght, G. Bersuker and M. C. DOWNER, “Charge trapping defects in Si/SiO₂/Hf_1-xSi_xO₂ film stacks characterized by spectroscopic second-harmonic generation,” J. Vac. Sci. Technol. B 29, 04D101 (2011).

114) S. Y. Kalmykov, S. A. Reed, S. A. Yi, V. Khudik, G. Shvets, A. Beck. E. Lefebvre, A. Pukhov, P. Dong, X. Wang, Y. Zhao, W. Henderson, M. Martinez, E. Gaul, T. Ditmire and M. C. DOWNER, “Numerical modeling of multi-GeV laser wakefield accelerator driven by a self-guided petawatt pulse,” New J. Phys. 12 045019.

113) S. Y. Kalmykov, S. A. Yi, A. Beck, A. F. Lifschitz, X. Davoine, E. Lefebvre, V. Khukik, G. Shvets and M. C. Downer, "Dark-current-free petawatt laser-driven wakefield accelerator based on electron self-injection into the expanding plasma bubble," Plasma Phys. Control. Fusion 53, 014006 (2011).

112) Robert Ehlert, Jinhee Kwon and M. C. DOWNER, “Optical second-harmonic and reflectance-anisotropy spectroscopy of reconstructed vicinal Si(001) surfaces,” J. Opt. Soc. Am. B 27, 981-989 (2010).

111) S. Y. Kalmykov, S. A. Reed, S. A. Yi, V. Khudik, G. Shvets, A. Beck, E. Lefebvre, A. Pukhov, P. Dong, X. Wang, Y. Zhao, W. Henderson, M. Martinez, E. Gaul, T. Ditmire and M. C. DOWNER, "Laser wakefield electron acceleration on Texas petawatt facility: Towards multi-GeV electron energy in a single self-guided stage," High Energy Density Physics 6, 200-206 (2010).

110) A. V. Arefiev, X. Gao, M. R. Tushentsov, X. Wang, B. Shim, B. N. Breizman and M. C. DOWNER, "Size distribution and mass fraction of microclusters in laser-irradiated plasmas," High Energy Density Physics 6, 121-127 (2010).

109) P. Dong, S. A. Reed, S. A. Yi, S. Y. Kalmykov, Z. Li, G. Shvets, M. C. DOWNER, N. H. Matlis, W. P. Leemans, C. McGuffey, S. S. Bulanov, V. Chvykov, G. Kalintchenko, K. Krushelnick, A. Maksimchuk, T. Matsuoka, A. G. R. Thomas and V. Yanovsky, "Holographic visualization of laser wakefields," New J. Phys. 12 (2010) 045016.

108) P. Dong, S. A. Reed, S. A. Yi, S. Y. Kalmykov, G. Shvets, M. C. DOWNER, N. H. Matlis, W. P. Leemans, C. McGuffey, S. S. Bulanov, V. Chvykov, G. Kalintchenko, K. Krushelnick, A. Maksimchuk, T. Matsuoka, A. G. R. Thomas and V. Yanovsky, "Visualization of plasma bubble accelerators using frequency domain shadowgraphy," High Energy Density Physics 6, 153-156 (2010).

107) P. Dong, S. A. Reed, S. A. Yi, S. Y. Kalmykov, G. Shvets, M. C. DOWNER, N. H. Matlis, W. P. Leemans, C. McGuffey, S. S. Bulanov, V. Chvykov, G. Kalintchenko, K. Krushelnick, A. Maksimchuk, T. Matsuoka, A. G. R. Thomas and V. Yanovsky, "Formation of optical bullets in laser-driven plasma bubble accelerators," Phys. Rev. Lett. 104, 134801 (2010).

106) Y. Sentoku and M. C. DOWNER, "Heat transport in solid target following relativistic laser-matter interaction," High Energy Density Physics 6, 268-273 (2010).

105) J. Price, Y. Q. An, P. Lysaght, G. Bersuker and M. C. DOWNER, "Resonant photo-ionization of defects in Si/SiO2/HfO2 film stacks observed by second-harmonic generation," Applied Physics Letters 95, 052906 (2009).

104) H. Langhoff, B. T. Bowes, M. C. DOWNER, B. Hou and J. Nees, "Surface energy transport following relativistic laser-solid interaction," Phys. Plasmas 16, 072702 (2009).

103) N. Salivati, Y. Q. An, M. C. DOWNER, and J. G. Ekerdt, "Hot-wire chemical vapor deposition of silicon nanoparticles on fused silica," Thin Solid Films 517, 3481-3483 (2009).

102) W. Grigsby, B. T. Bowes, D. A. Dalton, A. B. Berstein, S. Bless, M. C. DOWNER, E. Taleff, J. Colvin and T. Ditmire, "Picosecond time-scale dynamics of short pulse laser-driven shocks in tin," J. Appl. Phys. 105, 093523 (2009).

101) Jimmy Price, Y. Q. An and M. C. DOWNER, "Optical second-harmonic generation study of charge trapping dynamics in HfO2/SiO2 films on Si(100)," phys. stat. sol. (c) 5, 2667-2670 (2008).

100) A. Wirth, J. Wei, J. J. H. Gielis, P. Figliozzi, J. Rafaelsen, Y. Q. An and M. C. DOWNER, "Second-harmonic spectroscopy of Si nanocrystals embedded in silica," phys. stat. sol. (c) 5, 2662-2666 (2008).

99) R. Ehlert, Jinhee Kwon and M. C. DOWNER, "Optical second-harmonic and reflectance-anisotropy spectroscopy of molecular adsorption at Si(001) step-edges," phys. stat. sol. (c) 5, 2551-2555 (2008).

98) Jimmy Price, Y. Q. An and M. C. DOWNER, "Optical second-harmonic generation study of charge trapping dynamics in HfO2/SiO2 films on Si(100)," phys. stat. sol. (c) 5, 2667-2670 (2008).

97)   A. Maksimchuk, S. Reed, S. S. Bulanov, V. Chvykov, G. Kalintchenko, T. Matsuoka, N. H. Matlis, S. Kalmykov, G. Shvets, M. C. DOWNER, C. R. Vane, J. R. Beene, D. Stracener, and D. R. Schultz, "Studies of laser wakefield structures and electron acceleration in underdense plasmas," Phys. Plasmas 15, 056703 (2008).

96) F. Grigsby, D. Peng, M. C. DOWNER, "Chirped-pulse Raman amplification for two-color high-intensity laser experiments," J. Opt. Soc. Am. B  25, 346-350 (2008).

95) K. Wu, R. Carriles and M. C. DOWNER, "Phase-sensitive electric-field-induced second-harmonic microscopy of metal-semiconductor junctions," J. Opt. Soc. Am. B 24, 2736-2740 (2007).

94) An, Y. Q., R. Carriles, and M. C. DOWNER, "Absolute phase and amplitude of second-order nonlinear optical susceptibility components at Si(001) interfaces," Physical Review B (Condensed Matter and Materials Physics) 75(24): 241307.

93) B. Shim, G. Hays, R. Zgadzaj, T. Ditmire, and M. C. DOWNER (2007), "Enhanced Harmonic Generation from Expanding Clusters," Phys. Rev. Lett. 98, 123902 (2007).

92) Pfeifer, T. and M. C. Downer (2007). "Direct experimental observation of periodic intensity modulation along a straight hollow-core optical waveguide." Journal of the Optical Society of America B-Optical Physics 24(5): 1025-1029.

91) Kwon, J., M. C. Downer, et al., "Second-harmonic and reflectance-anisotropy spectroscopy of vicinal Si(001)∕SiO₂ interfaces: Experiment and simplified microscopic model", Phys. Rev. B 73, 195330 (2006).

90) N. H. Matlis, S. Reed, S. S. Bulanov, V. Chvykov, G. Kalintchenko, T. Matsuoka, P. Rousseau, V. Yanovsky, A. Maksimchuk, S. Kalmykov, G. Shvets and M. C. DOWNER, "Snapshot of laser wakefields", Nature Physics 2, 749 - 753 (2006).

89) R. Carriles, J. Kwon, Y. Q. An, J. C. Miller, M. C. Downer, J. Price, and A. C. Diebold, "Second-harmonic generation from Si/SiO2/Hf(1-x)SixO2 structures," Appl. Phys. Lett. 88, 161120 (2006).

88) Carriles, R., J. Kwon, et al. (2006). "Optical characterization of process-dependent charging in hafnium oxide structures," J. Vac. Sci. Technol. B 24, 2160 (2006).

87) Carriles, R., Y. Q. An, et al. (2005). "Frequency-domain measurement of second harmonic phase," physica status solidi (b) 242, 3001 (2005).

86) J. Nees, B. Hou, B. T. Bowes, N. Naumova, A. Mordovanakis, E. Power, M. C. Downer, and G. Mourou, Distinctive physical effects and applications approaching the relativistic lambda-cubed regime,” IEEE Selected Topics in Quantum Electronics 12, 223 (2006).

 85) B. T. Bowes, H. Langhoff, M. C. Downer, M. Wilcox, B. Hou, J. Nees, and G. Mourou Femtosecond microscopy of radial energy transport in a micrometer-scale aluminum plasma excited at relativistic intensity,” Optics Letters 31, 116 (2006). Published in Virtual J. Ultrafast Science. (21 Feb 2006)

 84) L. Sun, P. Figliozzi, Y. Q. An, M. C. Downer, W. L. Mochan and B. S. Mendoza, “ Quadrupolar SHG enhancement in isotropic materials using two orthogonally polarized laser beams”, Optics Letters 30, 2287 (2005).

 83) P. Figliozzi, L. Sun, Y. Jiang, N. Matlis, B. Mattern, M. C. Downer, S. P. Withrow, C. W. White, W. L. Mochan and B. S. Mendoza, “Single-beam and enhanced two-beam second-harmonic generation from silicon nanocrystals by use of spatially inhomogeneous femtosecond pulses,” Phys. Rev. Lett. 94, 047401 (2005). Published in Virtual J. Nanoscale Science & Technol. (Feb. 14, 2005)

 82) M. Fomytskyi, C. Chiu, F. Grigsby and M. C. Downer, “Controlled plasma wave generation and particle acceleration through seeding of the forward Raman instability,” Phys. Plasmas 12, 023103 (2004)

 81) C. Chiu, M. Fomytskyi, F. Raischel, F. Grigsby, M. C. Downer and T. Tajima, “Laser accelerators for radiation medicine: a feasibility study,” J. Med. Phys. 31, 2042-2052 (2004)

 80) K. K. Kainz, K. R. Hogstrom, J. A. Antolak, P. R. Almond, C. D. Bloch, C. Chiu, M. Fomytskyi, F. Raischel, M. C. Downer and T. Tajima, “Dose properties of a laser accelerated electron beam and prospects for clinical application,” J. Med. Phys. 31, 2053-2067 (2004)

 79) R. Zgadzaj, E. W. Gaul, N. H. matlis, M. C. Downer, and G. Shvets, ;Femtosecond pump-probe study of preformed plasma channels,” J. Opt. Soc. Am. B 21, 1559-1567 (2004)

 78) P. T. Wilson, Y. Jiang, R. Carriles-Jaimes and M. C. Downer, Optical second harmonic spectroscopy with broadband femtosecond pulses,” J. Opt. Soc. Am. B 20, 2548-2561 (2003)

 77) E. Mishina, N. Tanimura, S. Nakabayashi, O. A. Aktsipetrov, M. C. Downer, “Photomodulated second harmonic generation at silicon-silicon oxide interfaces: from modelling to application,” Jpn. J. Appl. Phys. 42, 6731-6736 (2003)

 76) K. Wu, J. D. Canterbury, P. T. Wilson, and M. C. Downer, “Electric-field-induced second-harmonic microscopy,Phys. Stat. Sol. (c) 0, 3081-3085 (2003)

 75) Jinhee Kwon and M. C. Downer, Reflectance-difference and second-harmonic generation: a meeting of two surface spectroscopies,” Phys. Stat. Sol. (c) 0, 3055-3060 (2003)

 74) M. C. Downer, "A New Low for Nonlinear Optics", Science 298, 373-375 (2002).

 73) Y. Jiang, L. Sun, and M. C. Downer, "Second-harmonic spectroscopy of two-dimensional Si nanocrystal layers embedded in SiO2 films", Appled Physics Letters 81, 3034-3036 (2002).

 72) M. C. Downer, Y. Jiang, D. Lim, L. Mantese, P. T. Wilson, B. S. Mendoza, and V. I. Gavrilenko, "Optical second harmonic spectroscopy of silicon interfaces and nanocrystals", phys. stat. sol. (a) 188, 1371-1381 (2001).

 71) M. C. Downer, B. S. Mendoza, and V. I. Gavrilenko, "Optical second harmonic spectroscopy of semiconductor surfaces: advances in microscopic understanding", Surf. Interface Anal. 31, 966-986 (2001).

 70) Y. Jiang, P. T. Wilson, M. C. Downer, C. W. White, and S. P. Withrow, "Second-harmonic generation from silicon nanocrystals embedded in SiO2," Applied Physics Letters 78, 766-768 (2001).

 69) F. Breitling, R. S. Weigel, M. C. Downer, T. Tajima, "Laser pointing stability control by neural network in sub-microradian regime," Review of Scientific Instruments 72, 1339-1342 (2001).

 68) E. W. Gaul, S. P. Le Blanc, A. R. Rundquist, R. Zgadzaj, H. Langhoff, and M. C. Downer, "Production and characterization of a fully ionized He plasma channel," Applied Physics Letters 77, 4112-4114 (2000).

 67) N. Andreev, M. V. Chegotov, M. C. Downer, E. W. Gaul, N. M. Matlis, A. A. Pogosova, and A. R. Rundquist, "Propagation of intense laser pulses through inhomogeneous ionizing gas profiles," IEEE Transactions on Plasma Science 28, 1090-1097 (2000).

 66) D. Lim, M. C. Downer, J. G. Ekerdt, N. Arzate, B. S. Mendoza, V. Gavrilenko, and R. Wu,"Optical second harmonic spectroscopy of boron-reconstructed Si(001)," Physical Review Letters 84, 3406-3409 (2000).

 65) D. Lim, M. C. Downer, and J. G. Ekerdt,"Second-harmonic spectroscopy of bulk boron-doped Si(001)," Applied Physics Letters 77, 181-183 (2000).

 64) S. P. Le Blanc, E. W. Gaul, N. H. Matlis, A. Rundquist, and M. C. Downer, "Single shot measurement of temporal phase shifts by frequency domain holography,"Optics Letters 25, 764-766 (2000).

 63) L. Mantese, K. Selinidis, P. T. Wilson, D. Lim, Y. Jiang, J. G. Ekerdt, and M. C. Downer, "In-situ control and monitoring of doped and compositionally-graded SiGe films using spectroscopic ellipsometry and second harmonic generation," Applied Surface Science 154-155, 229-237 (2000).

 62) Y. S. Lee and M. C. Downer, "Reflected optical fourth harmonic generation at crystalline surfaces,"Thin Solid Films 364, 80-85 (2000).

 61) V. I. Gavrilenko, R. Q. Wu, M. C. Downer, J. G. Ekerdt, D. Lim, and P. Parkinson"Optical second-harmonic spectra of silicon ad-atom surfaces: theory and experiment," Thin Solid Films 364, 1-5 (1999).

 60) O. A. Aktsipetrov, A. A. Fedyanin, A. V. Melnikov, E. D. Mishina, A. N. Rubtsov, M. H. Anderson, P. T. Wilson, M. ter Beek, X. F. Hu, J. I. Dadap, and M. C. Downer, "dc-electric-field-induced and low-frequency electromodulation second-harmonic generation spectroscopy of Si(001)-SiO₂ interfaces,"Physical Review B-Condensed Matter 60 (12), 8924-8938 (1999).

 59) M. K. Grimes, Y.-S. Lee, A. R. Rundquist and M. C. Downer, "Experimental identification of 'vacuum heating' at femtosecond-laser-irradiated metal surfaces," Physical Review Letters 82, 4010-4013 (1999).

 58) T. Tajima, Y. Kishimoto, and M. C. Downer, "Optical properties of cluster plasma," Physics of Plasmas  6, 3759-64  (1999).

 57) P. T. Wilson, Y. Jiang, O. A. Aktsipetrov, E. Mishina and M. C. Downer, "Frequency domain interferometric second harmonic spectroscopy," Optics Letters 24, 496-498 (1999).

 56) R. W. Kempf, P. T. Wilson, M. C. Downer, E. D. Mishina and O. A. Aktsipetrov, "Third and fourth harmonic generation at Si-SiO2 interfaces in Si-SiO2-Cr MOS structures," Applied Physics B 68, 325-332 (1999).

 55) P. S. Parkinson, D. Lim, R. Bungener, M. C. Downer and J. G. Ekerdt, "Second harmonic spectroscopy of Ge/Si(001) and Si1-xGex(001)/Si(001)," Applied Physics B 68, 641-648 (1999).

 54) C. Fauser, E. W. Gaul, S. P. Le Blanc and M. C. Downer, "Guiding characteristics of a piezoelectric tube," Applied Physics Letters 73, 2902-2904 (1998).

 53) J. Koga, S. Kato, Y. Kishimoto, S. P. Le Blanc, and M. C. Downer, "Optical field ionization effects on the generation of wakefields with short pulse lasers," Nuclear Instruments and Methods in Physics Research A 410, 499-504 (1998).

 52) Y.-S. Lee and M. C. Downer,"Reflected fourth-harmonic radiation from a centrosymmetric crystal," Opt. Lett. 23, 918-920(1998).

 51) J.I. Dadap, Z. Xu, X. F. Hu, M.C. Downer, N.M.Russell, J.G. Ekerdt, and O.A.Aktsipetrov, "Second harmonic spectroscopy of a Si(001) surface during calibrated variations in temperature and hydrogen coverage," Phys. Rev. B56, 13367 (1997).

 50) X.F. Hu, Z. Xu, D. Lim, M. C. Downer, P.S. Parkinson, B. Gong, G. Hess, and J.G. Ekerdt, "In situ optical second harmonic generation monitoring of disilane adsorption and hydrogen desorption during epitaxial growth on Si(001)," Appl. Phys. Lett. 71, 1376 (1997).

 49) O.A. Aktsipetrov, A. A. Fedyanin, A.V. Melnikov, J.I. Dadap, X.F. Hu, M.H. Anderson, M. C. Downer, J.K. Lowell,"DC-electric-field-induced second harmonic generation spectroscopy of the Si(001)-SiO_2 interface," Thin Solid Films 294, 231 (1997).

 48) C.W. Siders, A.J. Taylor, and M. C. Downer, "Multipulse interferometric frequency-resolved optical gating," Opt. Lett. 22, 624 (1997).

 47) Y.-S. Lee, M. H. Anderson, and M. C. Downer, "Fourth harmonic generation at a crystalline GaAs(001) surface," Opt. Lett. 22, 973-975 (1997).

 46) J. I. Dadap, P.T. Wilson, M. ter Beek, M.H. Anderson, and M. C. Downer, "Femtosecond carrier-induced screening of dc-electric-field-induced second harmonic generation at the Si(001)/SiO₂ interface," Opt. Lett. 22, 901-903 (1997).

 45) Z. Xu, X.F. Hu, D. Lim, J.G. Ekerdt, and M. C. Downer, "Second harmonic spectroscopy of Si(001) surfaces: sensitivity to surface hydrogen and doping, and applications to kinetic measurements," J. Vac. Sci. Technol. B 15, 1059 (1997).

 44) O. A. Aktsipetrov, A.A. Fedyanin, J.I. Dadap, and M. C. Downer, "Dc-electric-field-induced second harmonic generation studies of surfaces and buried interfaces of Column IV semiconductors," Laser Physics6, 1142 (1996).

 43) S. P. Le Blanc, M. C. Downer, R. Wagner, S.-Y. Chen, A. Maksimchuk, G. Mourou, and D. Umstadter, "Temporal characterization of a self-modulated laser wakefield," Phys. Rev. Lett. 77, 5381 (1996).

 42) J. I. Dadap, X. F. Hu, M. Anderson, M. C. Downer, J. K. Lowell, O. A. Aktsipetrov, "Optical second harmonic spectroscopy of a Si(001) metal-oxide-semiconductor structure," Phys. Rev. B 53, (Rapid Comm.), 7607 (1996).

 41) C. W. Siders, S. P. Le Blanc, D. Fisher, T. Tajima, M. C. Downer, A. Babine, A. Stepanov, and A. Sergeev, "Laser wakefield excitation and measurement by femtosecond longitudinal interferometry," Physical Review Letters 76, 3570 (1996).

 40) C. W. Siders, S. P. Le Blanc, T. Tajima, M. C. Downer, A. Babine, A. Stepanov, A. Sergeev, "Plasma-based accelerator diagnostics based upon longitudinal interferometry with ultrashort optical pulses," IEEE Trans. Plasma Science,  24 (2) 301-315 (1996).

 39) J. I. Dadap, X. F. Hu, N. M. Russell, J. G. Ekerdt, M. C. Downer, and J. K. Lowell, "Analysis of second harmonic generation by unamplified, high repetition rate ultrashort laser pulses at Si(001) interfaces." IEEE Journal of Selected Topics in Quantum Electronics 1, 1145 (1995).

 38) C. W. Siders, N. C. Turner III, M. C. Downer, A. Babine, A. Stepanov, and A. Sergeev, "Blue-shifted third harmonic generation during ultrafast barrier suppression ionization of subatmospheric density noble gases", JOSA B 13, 330 (1996).

 37) K. Nakajima, D. L. Fisher, T. Kawakubo, H. Nakanishi, A. Ogata, Y. Kato, Y. Kitagawa, R. Kodama, K. Mima, H. Shiraga, K. Suzuki, K. Yamakawa, T. Zhang, Y. Sakawa, T. Shoji, Y. Nishida, N. Yugami, M. C. Downer, T. Tajima, "Observation of ultrahigh gradient electron acceleration by a self-modulated intense short laser pulse." Physical Review Letters 74, 4428 (1995).

 36) D. L. Fisher, T. Tajima, M. C. Downer, and C. W. Siders, "Envelope evolution of a laser pulse in an active medium," Physical Review E 51, 4860-4868 (1995).

 35) C. W. Siders, E. Gaul, M. C. Downer, A. Babine, A. Stepanov, "Self-starting femtosecond pulse generation from a Ti: sapphire laser synchronously pumped by a pointing-stabilized mode-locked Nd: YAG laser," Review of Scientific Instruments 65, 3140-3144 (1994).

 34) X. Y. Wang, D. M. Riffe, Y. S. Lee, and M. C. Downer, "Time-resolved electron temperature measurement in a highly excited gold target using femtosecond thermionic emission," Physical Review B 50, 8016 (1994).

 33) E. V. Vanin, A. V. Kim, A. M. Sergeev, and M. C. Downer, "Excitation of ultrashort bursts of harmonics of the radiation during ionization of a gas by an intense light pulse." Pis'ma Zh. Eksp. Teor. Fiz. 58, 964-969 (1993) [JETP Letters 58, 900-906 (1994)].

 32) J. I. Dadap, B. Doris, Q. Deng, M. C. Downer, J. K. Lowell, and A. C. Diebold, "Randomly-oriented angstrom-scale microroughness at the Si(100)/SiO₂ interface probed by optical second harmonic generation." Applied Physics Letters 64, 2139-2141 (1994).

 31) T. Dallas, M. Holtz, H. Ahn, and M. C. Downer, "Structural phase of femtosecond laser melted graphite." Physical Review B 49, 796-801 (1994).

 30) H. R. Choo, X. F. Hu, M. C. Downer, and V. P. Kesan, "Femtosecond ellipsometric study of nonequilibrium carrier dynamics in Ge and epitaxial Si_1-xGe_x." Applied Physics Letters 63, 1507-1509 (1993).

 29) D. M. Riffe, X. Y. Wang, M. C. Downer, D. L. Fisher, T. Tajima, J. L. Erskine, and R. M. More, "Femtosecond thermionic emission from metals in the space-charge-limited regime." Journal of the Optical Society of America B 10, 1424-1435 (1993).

 28) W. M. Wood, C. W. Siders, and M. C. Downer, "Femtosecond growth dynamics of an underdense ionization front measured by spectral blueshifting." IEEE Transactions on Plasma Science 21, 20-33 (1993).

 27) B. I. Penetrante, N. M. Bardsley, W. M. Wood, C. W. Siders, and M. C. Downer, "Ionization-induced frequency shifts in intense femtosecond laser pulses." Journal of the Optical Society of America B 9, 2032-2040 (1992).

 26) X. Y. Wang and M. C. Downer, "Femtosecond time-resolved reflectivity of hydrodynamically expanding metal surfaces", Optics Letters 17, 1450-1452 (1992).

 25) W. M. Wood, C. W. Siders, and M. C. Downer, "Measurement of femtosecond ionization dynamics of atmospheric density gases by spectral blueshifting." Physical Review Letters 67, 3523-3526 (1991).

 24) D. H. Reitze, H. Ahn, and M. C. Downer, "Optical properties of liquid carbon measured by femtosecond spectroscopy." Physical Review B 45, 2677-2693 (1992).

 23) J.I. Dadap, D.H. Reitze, G.B. Focht, and M. C. Downer, "Autocorrelation measurement of ultraviolet femtosecond pulsewidths by two-photon absorption in diamond", Optics Letters 16, 499-502 (1991).

 22) M. C. Downer, W.M. Wood, and J.I. Trisnadi, "Comment on 'Energy Conservation in the Picosecond and Subpicosecond Photoelectric Effect'." Physical Review Letters 65, 2832 (1990).

 21) K. Seibert, G.C. Cho, W. Kütt, H. Kurz, M. C. Downer, D.H. Reitze, J. Dadap, and A.M. Malvezzi, "Femtosecond carrier dynamics in graphite." PhysIcal Review B 42, 2842-2851 (1990).

 20) T.R. Zhang, H.R. Choo, and M. C. Downer, "Phase and group velocity matching for second harmonic generation of femtosecond pulses." Applied Optics 29, 3926-3933 (1990).

 19) D.H. Reitze, T.R. Zhang, W.M. Wood, and M. C. Downer, "Two-photon spectroscopy of silicon using femtosecond pulses at above gap frequencies", Journal of the Optical Society of America 7, 84-89 (1990).

 18) D.H. Reitze, X. Wang, H. Ahn, and M. C. Downer, "Femtosecond laser melting of graphite." Physical Review B 40, 11986-11989 (1989).

 17) G.W. Burdick, M. C. Downer, and D.K. Sardar, "A new contribution to spin-forbidden rare earth optical transition intensities: analysis of all trivalent lanthanides." Journal of Chemical Physics 191, 1511- 1520 (1989).

 16) O.R. Wood II, W.T. Silfvast, H.W.K. Tom, W.H. Knox, R.L. Fork, C.H. Brito-Cruz, M. C. Downer, and P.J. Maloney, "Effect of laser pulse duration on XUV emission from femtosecond and picosecond laser-produced Ta plasmas." Applied Physics Letters 53, 654-656 (1988).

 15) W.M. Wood, G. Focht, and M. C. Downer, "Tight focusing and blue shifting of millijoule femtosecond pulses from a conical axicon amplifier." Optics Letters 13, 984-986 (1988).

 14) M. C. Downer, G. W. Burdick, and D. K. Sardar, "A new contribution to spin-forbidden rare earth optical transition intensities: Gd³⁺ and Eu³⁺." Journal of Chemical Physics 89, 1787-1797 (1988).

 13) T.R. Zhang, G. Focht, P.E. Williams, and M. C. Downer, "Theory of intracavity frequency doubling in passively mode-locked femtosecond lasers." IEEE Journal of Quantum Electronics 24, 1877-1883 (1988).

 12) G. Focht and M. C. Downer, "Generation of synchronized ultraviolet and red femtosecond pulses by intracavity frequency doubling." IEEE Journal of Quantum Electronics 24, 431-434 (1988).

 11) M. C. Downer and C.V. Shank, "Ultrafast heating of silicon-on-sapphire by femtosecond optical pulses." Physical Review Letters 56, 761-764 (1986).

 10) W.H. Knox, R.L. Fork, M. C. Downer, R.H. Stolen, C.V. Shank, and J. Valdmanis, "Optical pulse compression to 8 femtoseconds at a 5 KHz repetition rate." Applied Physics Letters 46, 1120-1121 (1985).

 9) W.H. Knox, R.L. Fork, M. C. Downer, D.A.B. Miller, D.S. Chemla, C.V. Shank, A.C. Gossard, and W. Wiegmann, "Femtosecond dynamics of resonantly generated excitons in room temperature GaAs quantum wells." Physical Review Letters 54, 1306-1309 (1985).

 8) M. C. Downer, R.L. Fork, and C.V. Shank, "Femtosecond imaging of melting and evaporation at a photo-excited silicon surface", Journal of the Optical Society of America B 2, 595-599 (1985).

 7) W.H. Knox, M. C. Downer, R.L. Fork, and C.V. Shank, "Amplified femtosecond optical pulses and continuum generation at 5 KHz repetition rate." Optics Letters 9, 552-554 (1984).

 6) M. C. Downer, C.D. Cordero-Montalvo, and H. Crosswhite, "Study of new 4f⁷ levels of Eu²⁺ in CaF₂ and SrF₂ using two-photon absorption spectroscopy." Physical Review B 28, 4931-4943 (1983).

 5) M. C. Downer and A. Bivas, "Third and fourth order analysis of the intensities and polarization dependence of two-photon absorption lines of Gd³⁺ in LaF₃ and aqueous solution." Physical Review B 28, 3677-3696 (1983).

 4) M. C. Downer, A. Bivas, and N. Bloembergen, "Selection rule violation, anisotropy, and anomalous intensity of two-photon absorption lines in Gd³⁺: LaF₃." Optics Communications 41, 335-339 (1982).

 3) A. Bogdan, M. Downer, and N. Bloembergen, "Quantitative characteristics of pressure-induced four wave mixing signals observed with cw laser beams." Physical Review A 24, 623-626 (1981).

 2) A. Bogdan, M. Downer, and N. Bloembergen, "Quantitative characteristics of pressure-induced degenerate frequency resonance in four wave mixing." Optics Letters 6, 348-350 (1981).

 1) M. Dagenais, M. Downer, R. Neumann, and N. Bloembergen, "Two-photon absorption as a new test of the Judd-Ofelt theory." Physical Review Letters 46, 561-565 (1981).