Three kinds of coplanar waveguides （CPWs） are designed and fabricated on different silicon substrates---common low-resistivity silicon substrate （LRS）, LRS with a 3μm-thick silicon oxide interlayer, and high-resistivity silicon （HRS） substrate. The results show that the microwave loss of a CPW on LRS is too high to be used, but it can be greatly reduced by adding a thick interlayer of silicon oxide between the CPW transmission lines and the LRS.A CPW directly on HRS shows a loss lower than 2dB/cm in the range of 0-26GHz and the process is simple,so HRS is a more suitable CPW substrate.
An integratable distributed Bragg reflector laser is fabricated by low energy ion implantation induced quantum well intermixing.A 4 6nm quasi continuous wavelength tuning range is achieved by controlling phase current and grating current simultaneously,and side mode suppression ratio maintains over 30dB throughout the tuning range except a few mode jump points.
采用超低压(22×102Pa)选择区域生长(selective area growth,SAG)金属有机化学气相沉积(metal_organic chemical vapor deposition,MOCVD)技术成功制备了InGaAsP/InGaAsP级联电吸收调制器(electro absorption modulator,EAM)与分布反馈激光器(distributed feed backlaser,DFB)单片集成光源的新型光电器件.实验结果表明,采用该技术制备的器件具有良好的性能:激射阈值为19mA,出光功率为4·5mW,在5V的驱动电压下达到了20dB的消光比,器件3dB响应带宽达到了10GHz以上.应用这种新型器件,利用级联EAM的光开关效应,获得了重复率为10GHz、半高宽(full_width_at_half_maximum,FWHM)为13·7ps的超短光脉冲.
A new fabricating method is demonstrated to realize two different Bragg gratings in an identical chip using traditional holographic exposure. Polyimide is used to protect one Bragg grating during the first period. The technical process of this method is as simple as that of standard holographic exposure.
The 3-section SG-DBR tunable laser is fabricate d using an ion implantation quantum-well intermixing process.The over 30nm discontinuous tuning range is achieved with the SMRS greater than 30dB.
