光子学报, 2019, 48 (3): 0314002, 网络出版: 2019-04-02
飞秒激光在掺Nd3+光热敏折变玻璃中写入光波导
Nd3+∶Photo-thermo-refractive Glass Waveguides Written by Femtosecond Laser
集成光学 双线型波导 压低包层管状波导 飞秒激光光刻 掺Nd3+光热敏折变玻璃 Integrated optics Double line waveguide Tubular depressed cladding waveguide Femtosecond laser writing Nd3+ doped photo-thermo-refractive glass
摘要
利用中心波长1 028 nm、重复频率50 kHz、脉冲宽度220 fs的超短脉冲激光在掺Nd3+光热敏折变玻璃中刻写双线型和压低包层管状波导.研究了激光功率、波导双线间距、管状波导直径对近场模式的影响, 得到了两组导光模式较优的波导.利用波导的近场模式强度分布重构了其折射率分布图, 得到两类波导最大的折射率增加量分别为+7.0×10-4和+5.5×10-4.利用散射法测得双线型波导的传输损耗为1.29 dB/cm; 通过测量插入损耗得到压低包层管状波导的传输损耗小于1.95 dB/cm.利用飞秒激光在掺Nd3+光热敏折变玻璃中直接写入光波导, 在集成光学器件上具有广阔的应用前景.
Abstract
Femtosecond laser with central wavelength of 1 028 nm, repetition rate of 50 kHz and pulse width of 220 fs is used to write double line and tubular depressed cladding waveguides in Nd3+ doped photo-thermo-refractive glass. The influences of laser power, double line separation and diameters of tubular depressed cladding waveguide on the near-field modes of waveguides are investigated, and the waveguides with better guiding mode are obtained. Refractive index profile is reconstructed by intensity distribution of the near-field mode, the largest positive refractive index change for these two types of waveguides is +7.0×10-4 and +5.5×10-4, respectively. By using the scattering technique, the propagation loss of double line waveguide is about 1.29 dB/cm. The loss of tubular depressed cladding waveguide is less than 1.95 dB/cm by testing the insert loss. Therefore, waveguides inscribed directly by femtosecond laser in Nd3+ doped photo-thermo-refractive glass are promising candidates for the development of integrated optical device.
张泽宇, 安海涛, 王旭, 谢英武, 张华, 刘青, 陈立功, 杨波. 飞秒激光在掺Nd3+光热敏折变玻璃中写入光波导[J]. 光子学报, 2019, 48(3): 0314002. ZHANG Ze-yu, AN Hai-tao, WANG Xu, XIE Ying-wu, ZHANG Hua, LIU Qing, CHEN Li-gong, YANG Bo. Nd3+∶Photo-thermo-refractive Glass Waveguides Written by Femtosecond Laser[J]. ACTA PHOTONICA SINICA, 2019, 48(3): 0314002.