Fast Light and the Speed of Information Transfer in the Presence of Detector Noise
The phenomenon of fast-light pulse propagation has seen renewed interest in recent years, but its relationship to the <i>speed of information transfer</i> is still being debated. In this paper, we define the <i>speed of information transfer</i> as the propagation speed of a p...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IEEE
2009-01-01
|
| Series: | IEEE Photonics Journal |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/5232875/ |
| Summary: | The phenomenon of fast-light pulse propagation has seen renewed interest in recent years, but its relationship to the <i>speed of information transfer</i> is still being debated. In this paper, we define the <i>speed of information transfer</i> as the propagation speed of a point of constant signal-to-noise ratio (SNR) on the leading edge of a signal pulse. We use standard telecommunication analysis to include the effects of noise so that the bit-error rate (BER) can be calculated as a function of a variable decision time. We introduce the concept of a time-dependent Q-factor so that pulse arrival times can be compared at equivalent BERs. We show that when receiver noise is included in a gain-assisted fast-light system, the measured <i>speed of information transfer</i> can exceed the speed of light for an equivalent pulse travelling through a vacuum. |
|---|---|
| ISSN: | 1943-0655 |