Damage threshold and focusability of mid-infrared free-electron laser pulses gated by a plasma mirror with nanosecond switching pulses
X. Wang, T. Nakajima, H. Zen, T. Kii and H. Ohgaki, Applied Physics Letters 103, 191105 (2013).

Experimental demonstration of mode-selective phonon excitation of 6H-SiC by a mid-infrared laser with anti-Stokes Raman scattering spectroscopy
K. Yoshida, T. Sonobe, H. Zen, K. Hachiya, K. Okumura, K. Mishima, M. Inukai, H. Negm, K. Torgasin, M. Omer, T. Kii, K. Masuda and H. Ohgaki, Applied Physics Letters 103, 182103 (2013).

Pulse duration and wavelength stability measurements of a midinfrared free-electron laser
Y. Qin, H. Zen, X. Wang, T. Kii, T. Nakajima, H. Ohgaki, Optics Letters, Vol. 38, Pages 1068-1070 (2013).

Optimization of the New Designed FEL Beam Transport Line
K. Yoshida, H. Zen, K. Okumura, K. Shimahashi, M. Shibata, T. Komai, H. Imon, H. Negm, M. Omer, Y.W. Choi, R. Kinjo, T. Kii, K. Masuda, H. Ohgaki, Zero-Carbon Energy Kyoto 2012, Pages 205-216 (2013).