Time-Domain Measurement of Negative Group Delay in Negative-Refractive-Index Transmission-Line Metamaterials
- 4 May 2004
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Microwave Theory and Techniques
- Vol. 52 (5), 1449-1454
- https://doi.org/10.1109/tmtt.2004.827018
Abstract
We have simulated and constructed a one-dimensional metamaterial composed of a periodically loaded transmission line that exhibits both negative and positive group velocities in a band of effective negative index of refraction. The negative group velocity or, equivalently, the negative group delay, is demonstrated theoretically and experimentally in the time domain using modulated Gaussian pulses. Due to this negative delay, we can show an output pulse peak emerging from the loaded transmission line prior to the input peak entering the line, i.e., the output pulse precedes the input pulse. The fact that this surprising behavior does not violate the requirements of relativistic causality is illustrated with time-domain simulations, which show that discontinuities in the pulse waveforms are traveling at exactly the speed of light in vacuum. The pulse-reshaping mechanism underlying this behavior is also illustrated using time-domain simulations.Keywords
This publication has 20 references indexed in Scilit:
- Negative group delay and superluminal propagation: an electronic circuit approachIEEE Journal of Selected Topics in Quantum Electronics, 2003
- Abnormal wave propagation in passive mediaIEEE Journal of Selected Topics in Quantum Electronics, 2003
- Time-domain detection of superluminal group velocity for single microwave pulsesPhysical Review E, 2000
- Frequency-domain detection of superluminal group velocity in a distributed Bragg reflectorIEEE Journal of Quantum Electronics, 2000
- Dual Optical Tunneling Times in Frustrated Total Internal ReflectionPhysical Review Letters, 1997
- VI: Tunneling Times and SuperluminalityProgress in Optics, 1997
- Two theorems for the group velocity in dispersive mediaPhysical Review A, 1993
- On superluminal barrier traversalJournal de Physique I, 1992
- Observation of negative velocity pulse propagationPhysics Letters A, 1985
- Linear Pulse Propagation in an Absorbing MediumPhysical Review Letters, 1982