APPARATUS AND METHOD FOR STRENGTHENING TERAHERTZ SIGNAL ON THE BASIS OF HOLLOW-CORE METAL WAVEGUIDE OPTICAL FIBER

摘要

An apparatus and method for strengthening a terahertz signal on the basis of a hollow-core metal waveguide optical fiber. Simple devices, such as a beam splitter (2), planar reflective mirrors (3, 4, 5, 6, 14, 15), a beam combiner (9), and an adjustable mechanical delay system, are used to generate a specific time-phase delay between two 800-nm light beams split by the beam splitter (2), then converge the same in a hollow-core metal waveguide optical fiber (10), and sequentially align the same with 400-nm light pulses, such that a non-linear reaction occurs to ionize a gas in the optical fiber to generate terahertz waves. The property of total internal reflection of the hollow-core metal waveguide optical fiber (10) is utilized to concentrate and propagate the generated terahertz light waves. The present invention prevents terahertz waves from being largely absorbed by moistures in the air, improves energy loss of the terahertz waves, and thus overcomes the problem of poor terahertz wave conversion efficiency in which a non-linear reaction of two light beams having different wavelengths lasts only for a short time during terahertz wave generation based on an air filamentation method. The present invention effectively enhances the signal strength of a terahertz wave to 3 times, and has simple operation and low costs.