27 March 2013 Tunable picosecond THz-wave generation based on trapezoidal MgO:LiNbO3 crystal in novel pentagram-shaped pump-enhancement cavity
Author Affiliations +
Abstract
It is well known that lithium niobate (LiNbO3) has excellent characteristics for efficient tunable/broadband THz-wave generation. Over the last few years, we have investigated novel THz-wave sources based on MgO-doped LiNbO3 (MgO:LiNbO3), and have succeeded in developing a tunable picosecond THz-wave source by using a novel pentagramshaped pump-enhancement cavity. One of the limiting factors in efficient THz-wave generation is the strong absorption by MgO:LiNbO3 in THz-wave region. To overcome this problem, we employ a surface-emitted configuration which consists of a trapezoidal MgO:LiNbO3 crystal and a pump-enhancement cavity folded in the shape of a pentagram. The pentagram-shaped cavity is designed for the noncollinear dual resonance of both pump and one of the down-converted waves. As a result, 1.5-ps pump pulses from a mode-locked Ti:sapphire laser operating at 780 nm allow tunable THzwave generation via parametric down-conversion resulting from stimulated phonon-polariton scattering in the MgO:LiNbO3 crystal. By slightly translating the position of one of the cavity mirrors, we experimentally find that the THz-wave frequency is tunable in the range from 0.1 to 3.5 THz with the average output power of dozens of nanowatts. The maximum THz-wave average power is up to 40 nW around 2 THz at the pump power of 800 mW, which is several times higher than the THz-wave output generated by using rectangular MgO:LiNbO3 crystals for Si-prism-coupled configuration under the same pump condition.
© (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Yuma Takida, Yuzuru Tadokoro, Hiroshi Kumagai, Shigeki Nashima, Ataru Kobayashi, "Tunable picosecond THz-wave generation based on trapezoidal MgO:LiNbO3 crystal in novel pentagram-shaped pump-enhancement cavity", Proc. SPIE 8604, Nonlinear Frequency Generation and Conversion: Materials, Devices, and Applications XII, 86041F (27 March 2013); doi: 10.1117/12.2001627; https://doi.org/10.1117/12.2001627
PROCEEDINGS
6 PAGES


SHARE
RELATED CONTENT


Back to Top