对基于SU-8紫外负性光刻胶的无源-有源集成式电光开关进行了系统的研究。首先用物理掺杂的方法制备出价格低廉、性能良好的主客掺杂型电光材料DR1/SU-8,反射法测量其电光系数约为11.5pm/V@1310nm。为减小器件的插入损耗,设计了有源芯层为DRl/SU-8、无源芯层为SU-8的倒脊形混合集成式波导结构。制作完CPW行波电极后,对器件进行接触极化。实验测得开关的上升时间和下降时间分别为5.6μs和5.2μs,插入损耗为13.8dB,与只用DRl/SU-8作为波导芯层的器件相比,插入损耗减小了约2.8dB。实验结果表明,这种无源一有源集成式电光波导有效地减小了器件的插入损耗,为制备低损耗的电光器件和单片多功能集成器件奠定了一定的基础。
In this paper, a detailed investigation on SU-8 based passive-active integrated electro-optic (EO) switch is reported. First,the EO material is synthesized with a simple physical doping process by mixing disperse red 1 (DR1) in SU-8 thinner and SU-8 (from MicroChem Corp. ) solution,and the EO material presents a high EO coefficient of 11.5 pm/V at the wavelength of 1310 nm. In order to reduce the insertion loss of the device, we design and fabricate an inverted-rib type of hybrid integrated waveguide with DR1/SU-8 as the active core layer and SU-8 as the passive core layer. After fabricating CPW electrode,we pole the device by contact poling method. Under 1 550 nm wavelength,the switching time and the insertion loss of the device are measured. The measuring results show that the rise time and fall time of the device are 5.6 μs and 5.2 μs,respectively. And the device has a low insertion loss of 13.8 riB,which is reduced by 2.8 dB compared with that of the EO waveguide only taking DR1/SU-8 as the core layer. This type of passive-active integrated EO waveguide can reduce the insertion loss effectively,and establish foundation for fabricating low loss EO devices and monolithic multi-function integrated devices.