摘要
利用飞秒脉冲激光在时域内对铁电体KDP(KH2 PO4 )进行冲击受激拉曼散射 (ISRS)实验研究 ,在激发光束夹角θ=0 .38°情况下 ,发现了KDP软模与光耦合所形成的电磁耦合波子弱衰减低频振荡的冲击受激拉曼散射响应信号 ,其周期随着温度接近相变温度Tc 而逐渐增大 ,其特性可用铁电体软模在Tc 温度附近频率的变化规律ω2 =α0 (T -Tc)来描述 ,这里系数α0 ≈ 16× 10 2 0 s2 K- 1 。
Femtosecond time resolved impulsive stimulated Raman scattering (ISRS) experiments on KDP soft modes are studied. The ISRS weakly attenuating and low frequency response of polariton on KDP soft modes coupling with light is observed at the crossing angle θ=0.38°. The period increases gradually with temperature approaching to the transition temperature T c. The property can be described with Cochran′s formula ω 2=α 0(T-T c) near T c for ferroelectric soft mode, where α 0≈16×10 20 s 2K -1 ?
出处
《光学学报》
EI
CAS
CSCD
北大核心
2002年第6期654-657,共4页
Acta Optica Sinica
