Generation of coherent terahertz pulses in ruby at room temperature

Elena Kuznetsova,¹ Yuri Rostovtsev,¹ Nikolai G. Kalugin,¹ Roman Kolesov,¹ Olga Kocharovskaya,¹ and Marlan O. Scully^1,2

¹Institute for Quantum Studies and Department of Physics, Texas A&M University, College Station, Texas 77843, USA

²Princeton Institute for Material Science and Department of Mechanical and Aerospace Engineering, Princeton University, New Jersey 08544, USA

(Received 8 May 2006; published 29 August 2006)

We have shown that a coherently driven solid state medium can potentially produce strong controllable short pulses of THz radiation. The high efficiency of the technique is based on excitation of maximal THz coherence by applying resonant optical pulses to the medium. The excited coherence in the medium is connected to macroscopic polarization coupled to THz radiation. We have performed detailed simulations by solving the coupled density matrix and Maxwell equations. By using a simple V-type energy scheme for ruby, we have demonstrated that the energy of generated THz pulses ranges from hundreds of pico-Joules to nano-Joules at room temperature and micro-Joules at liquid helium temperature, with pulse durations from picoseconds to tens of nanoseconds. We have also suggested a coherent ruby source that lases on two optical wavelengths and simultaneously generates THz radiation. We discussed also possibilities of extension of the technique to different solid-state materials.

©2006 The American Physical Society

URL: http://link.aps.org/abstract/PRA/v74/e023819

doi:10.1103/PhysRevA.74.023819

PACS: 42.50.Gy, 42.65.Ky