Nematic liquid crystal optical amplifier consisting of layered structures.
Coherent amplification was observed in an optical structure with multilayer C(60) doped nematic films, in which photorefractive gratings working in the Raman-Nath regime were created, leading to an asymmetric energy transfer in two-beam coupling. This multilayer optical structure exhibited exponential dependence of the signal gain on the number of nematic layers when higher-order diffractions were negligibly small. A gain of the 0.1 microW signal as high as approximately 4000 was achieved in the six-layer sample at a low dc voltage of 1.2 V and a low pump beam power of 8 mW. The gain of this ultrahigh sensitive six-layer sample depended strongly on the pump to signal beam power ratio as well as the power of the signal.
Department of Physics, Harbin Institute of Technology, Harbin 150001, China. peiyanbo@hit.edu.cn
Yanbo
Y
Pei
Fengfeng
F
Yao
Jianlong
J
Zhang
Chunfeng
C
Hou
Xiudong
X
Sun