**4. References**


**3** 

*I. R. Iran* 

**Dynamic All Optical Slow Light** 

S. M. Hamidi2, Amir Hassanpour3 and S. Amiri4

*4Institute for Research in Fundamental Sciences, Tehran* 

Alireza Bananej1, S. Morteza Zahedi1,

*1Laser and Optics Research School, NSTRI* 

, It can be shown that group velocity of

, the speed of light can be controlled and

**Tunability by Using Nonlinear One** 

**Dimensional Coupled Cavity Waveguides** 

*2Laser and Plasma research Institute, Shahid Beheshti University, Evin, Tehran* 

Light propagation at slow speed, delaying light, has a tremendous role in a wide range of advanced technology from peta-bit optical networks to even laser fusion technology [1,2]. Recently, it was realized that delaying of an optical signal is useful for a number of applications such as optical buffering, signal processing, optical sensing and enhancement of optical nonlinearity in materials [3]. Also, as a consequence of important role of fiber lasers in laser fusion technology, coherent beam combining of several fiber lasers for achieving high power output is a crucial problem in future fusion technology. This task can be overcome by using proper engineered photonic components for achieving specific group delay time [2].

Generally, the speed of light is related to the refractive index of the propagation medium.

d c

the medium and *k* is the propagation constant. Evidently, as a reason of limited optical materials and hence, limited refractive indices, it is not possible to slow down the speed of light sufficiently or adjust it to a specific desired value. However, it is obvious that by

dk dn n() <sup>d</sup>

is the light frequency, *c* is the speed of light in vacuum, *n* is the refractive index of

d , slow down the speed of light can be obtained sufficiently.

v

g

v

d

dk 

**1. Introduction** 

Where,

in a special case when dn <sup>1</sup>

From the basic definition of group velocity, <sup>g</sup>

controlling the rate of refractive index changing, dn

d

light in a medium can be derived as [4]:

*3Department of physics, K. N. Toosi University of Technology, Tehran* 

K. Panajotov, B. Ryvkin, J. Danckaert, M. Peeters, H. Thienpont, I. Veretennicoff, IEEE Photon. Technol. Lett. 10 (1998) 6.

D.S. Song, Y.J. Lee, H.W. Choi, Y.H. Lee, Appl. Phys. Lett. 82 (2003) 3182.
