Cherenkov phase matched THz-wave generation with surfing configuration for bulk Lithium Nobate crystal

Abstract

We demonstrated a Cherenkov phase matched THz-wave generation with surfing configuration for bulk lithium niobate crystal. THz-wave output was enhanced about 50 times by suppressing phase mismatching for THz-wave propagation direction. The suppression was achieved by combining two pumping waves with dual wavelength with finite angle, and THz-frequency was controllable by changing the angle within 2.5 degrees range. Higher frequency THz-wave generation at around 4.0 THz was successfully obtained by the method.

Half Cycle Terahertz Pulse Generation by Prism-Coupled Cherenkov Phase-Matching Method

“…A Si prism was coupled along the (001) plane of the DAST crystal because the as-grown DAST has a very flat surface in the plane. A dual-wavelength potassium titanium oxide phosphate (KTP) optical parametric oscillator (OPO) with a pulse duration of 15 ns, a pulse energy of 1.5 mJ, and 1300-1600-nm tunable range was used as a pump, as described in our previous work [12][13][14][15]. The polarizations of the two pumps were parallel to the a-axis of the DAST crystal, which has the highest nonlinear coefficient component, and THz radiation was generated parallel to the a-axis.…”

“…Surface-emitting THz generation can overcome these problems [5]; absorption is minimized because the THz-frequency wave is generated at the crystal surface: the Cherenkov-type radiation is generated as surface emission [6][7][8][9][10][11]. We have previously demonstrated a Cherenkov phase-matching method for monochromatic THz generation via difference frequency generation (DFG) using lithium niobate crystals [12][13][14][15]. We were able to generate monochromatic THz radiation with wide tunability in the range of 0.1-7.2 THz.…”

Investigation of Terahertz Generation from Bulk and Periodically Poled LiTaO3Crystal with a Cherenkov Phase Matching Scheme

“…Difference frequency generation (DFG) with two closely spaced laser frequencies ω 1 and ω 2 in second-order nonlinear optics crystals is one of the promising processes for efficient monochromatic THz wave output in the wide frequency tuning range and for room temperature operation [5,6]. Recently, high-efficiency THz wave generation based on DFG employing Cherenkov phase matching has been intensively researched [7][8][9]. THz wave generation with Cherenkov phase matching is an attractive scheme because strong THz absorption originated from lattice vibration modes of the nonlinear optical crystal can be overcome.…”

THz-wave sensing via pump and signal wave detection interacted with evanescent THz waves

“…The purpose of the present Letter is to show possibility of this method. Here, we show, to the best of our knowledge, the first demonstration of this sensing method using an evanescent THz wave by detecting pump waves.In this method, we use a THz wave generated by Cherenkov phase matching using a lithium niobate crystal (LiNbO 3 ) [8][9][10][11]. These monochromatic THz waves have wide tunability, over the range of 0.…”