摘要
介绍了高品质因子(Q)回音壁模式(WGM)Si O2光学微球腔和锥形光纤耦合器的制备方法。应用窄线宽(300 kHz)单模NewFocus可调谐激光器(1520～1570 nm)作为激发光源,使用直径1.2μm锥形光纤激发直径150μm的Si O2微球腔的光学模式,得到了其形貌共振谱线。从微球腔的温度分布出发,结合Si O2材料的热膨胀以及热光效应折射率变化机理,分析了微球腔在高功率光激发下热效应引起的共振谱平移(2.5 GHz/℃)。实验表明,控制WGM激发功率,可有效抑制微球腔的热效应,且易于实现稳定的高Q模式。调整锥形光纤耦合激发角度,可以较好地抑制微球腔高阶模式,测得其共振谱线宽为22 MHz,对应的微球腔Q值为107。
Fabrication methods of SiO2 optical microsphere cavities and tapered fibers are introduced.Using a tunable single-mode NewFocus laser（short-term linewidth of 300 kHz） with an adjustable extent of 1520～1570 nm as the excitation optical source,whispering gallery modes（WGM） of microsphere with a diameter of 150 μm are achieved through coupling a tapered fiber with waist diameter of 1.2 μm.The microsphere and the tapered fiber are all fabricated by experimental laboratory setup.Based on the microsphere cavity′s temperature distribution,binding the thermal expansion coefficient and the thermo-optical refractive index effects,resonant spectrum shift（2.5 GHz/℃）induced by the high pump power in the microcavity is analyzed.The experiments indicate that controlling the WGM pump power is an effective way to suppress microcavity thermal effects,and in this way it is easy to fulfill a stable high quality factor（Q） model.Through adjusting the tapered fiber pumping angle,higher-modes are suppressed effectively,and an ultra-narrow linewidth about 22 MHz is measured.The corresponding Q of this microsphere is 107.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2010年第7期1789-1793,共5页
Chinese Journal of Lasers
基金
国家973规划前期(2009CB326206)
国家自然科学基金(60707014和60778029)
重点实验室基金(9140C1204040909)
总装创新项目(7130907)
山西省自然科学基金(20091105916和2010011003)
山西省高等学校优秀青年学术带头人支持计划资助
山西省研究生优秀创新项目(20093076)资助课题
关键词
激光技术
光学微腔
回音壁模式
品质因子
倏逝场激发
热效应
laser technique
optic microcavity
whispering gallery modes
quality factor
evanescent wave exciting
thermal effect
