%0 Journal Article
%T Terahertz Generation in an Electrically Biased Optical Fiber: A Theoretical Investigation
%A Montasir Qasymeh
%J International Journal of Optics
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/486849
%X We propose and theoretically investigate a novel approach for generating terahertz (THz) radiation in a standard single-mode fiber. The optical fiber is mediated by an electrostatic field, which induces an effective second-order nonlinear susceptibility via the Kerr effect. The THz generation is based on difference frequency generation (DFG). A dispersive fiber Bragg grating (FBG) is utilized to phase match the two interacting optical carriers. A ring resonator is utilized to boost the optical intensities in the biased optical fiber. A mathematical model is developed which is supported by a numerical analysis and simulations. It is shown that a wide spectrum of a tunable THz radiation can be generated, providing a proper design of the FBG and the optical carriers. 1. Introduction Due to a lack of generation and detection instrumentation, the electromagnetic spectrum between infrared light and microwave radiation, traditionally known as the terahertz (THz) gap, has not been fully explored [1]. The application of THz radiation was traditionally limited to astronomy and analytical science. Recent advances in photonics have laid the groundwork for the realization of THz sources and detectors for applications in biomedical imaging [2] and ultra-fast communications [3]. As THz sources become more readily available, THz technology is being increasingly used in a variety of fields, including information and communications technology, biology and medical sciences, nondestructive evaluation, homeland security, quality control of food and agriculture, global environmental monitoring, and ultrafast computing, to mention a few examples [4]. The wide and crucial applications of THz waves are due to its unique way of interacting with materials. For example, in medical science, the ability of THz wave to probe intermolecular interactions enables it to provide both structural and functional information. Consequently, and considering its safe, accurate, and economical features, THz radiation promisesto alternate other scanning methods such as high frequency ultrasound, magnetic resonance imaging, and near-infrared imaging [4]. This promising technology has the potential to lead the way many diseases are diagnosed and ultimately cured. In the past few years, several techniques have been proposed to generate THz waves. Generation of CW and pulsed THz waves have been both investigated. Techniques to generate CW THz waves include quantum cascade laser (QCL) [5], directly multiplied source [6], backward wave oscillator (BWO) [7], germanium laser [8], and silicon impurity
%U http://www.hindawi.com/journals/ijo/2012/486849/