Dynamic modulation of slow light by electro-optic effect in photonic
crystal coupled resonator optical waveguide
Changhong Li
1
, Yong Wan
2
, Ruitao Yu
1
1College of Automation Engineering, Qingdao University, Qingdao, 266071, PR. China
2College of Physics Science, Qingdao University, Qingdao, 266071, PR. China
ABSTRACT
A novel structure of photonic crystal coupled resonator optical waveguide (PC-CROW) with elliptical rod around
cavity is proposed to realize compact, high sensitivity modulated and high-performance buffering application. By
adjusting the long axis and short axis of the elliptical rods, the slow light and buffer performance of PC-CROW are
optimized. As a
e
=0.42a, b
e
=0.20a, the group velocity is below 2.3053×10
-4
c, simultaneously, the buffer capacity C and
delay time T
s
reach the optimum value. Then the dynamic modulation of the slow light and buffer performance based on
this optimized structure has been discussed systematically. The guided mode shifts linearly to short wavelength and
delay time decreases exponentially as the external modulated voltage increases. And the modulation sensitivities are
about 3.0nm/mV and 0.467ns/mV, respectively. These results show that the proposed structure has considerable potential
for optical buffering application.
Key words: slow light, dynamic modulation, buffer capability, photonic crystal, coupled resonator optical
waveguide.
1. INTRODUCTION
Slow light with an ultra low group velocity is of great interest because of its potential applications to optical
delay lines, all-optical buffers, optical storages, and enhanced matter interaction
[1-4]
. All these are desired in future
all-optical communications and information processing systems. Because of the unique nano-structure, attractive
slow light properties and room-temperature operation, the slow light transmission in photonic crystal (PC) has been
intensively investigated both in experiment and theory. Compared with photonic crystal line defect waveguide
(PCW), the photonic crystal coupled resonator optical waveguide (PC-CROW) has more flat band and small group
velocity
[5,6]
, which can be used to produce high-performance optical delay lines, optical buffers and optical
storages.
In real application, the controllable all-optical devices are the most critical components
[7]
. For example,
all-optical buffers and optical storages must be able to turn on to store and turn off to release optical data at a very
rapid rate by an external command. Due to the ultra high response speed on the order of nanosecond and attractive
large electro-optic coefficient (10pm/V to 170pm/V)
[8]
, we design the slow light PC-CROW in polymers. In
addition, there is a significant predominance of PC is that the electro-optic tunableness would be enhanced by the
low group velocity in PC.
Intl. Symposium on Optoelectronic Technology & Application 2014: Laser Materials Processing; & Micro/Nano Technologies,
edited by N. Kaiser, B. Li, Y. Ji, G. Verhaeghe, M. Zhong, B. Lu, H. Wang, M. C. Leu, Y. Yan, H. Xie, D. Zhang, G. Zhou,
Proc. of SPIE Vol. 9295, 929518 · © 2014 SPIE · CCC code: 0277-786X/14/$18 · doi: 10.1117/12.2072186
Proc. of SPIE Vol. 9295 929518-1