Study On Optical Modulators Based On Graphene

In the recent years, graphene has stirred up particular interest owing to its excellent photoelectric properties. It has huge potential in the next generation of micro-nano optoelectronics. A series of graphene-based optical modulators have been fabricated successfully with high performance since 2011, which has indicated its bright future. However, these devices also suffer from weak interaction between graphene and light, low modulation speed, complicated fabrication process and a low yield of working devices. To end these problems, ring resonator and graphene are employed as the substrate and active material to fabricate optical modulators with high performance in this article. More details are as follow:1, Study on the electro-optic modulator with graphene coated on a ring resonatorTo strengthen the interaction between graphene and light so that higher modulation depth and smaller device footprint will be achieved. In this article, a hybrid structure with graphene coated on a ring resonator is employed to fabricate a electro-optic modulator. Its modulation depth and speed are 2 dB and 125 MHz, respectively. In addition, the active area of the device is as low as 13 μm2. The results promise a novel architecture for optical interconnects.2, Study on a highly efficient thermo-optic microring modulator assisted by grapheneBeside the outstanding photoelectrical properties, graphene also has excellent thermaldynamic properties, especially the high thermal conductivity. The combination with graphene on a silicon chip can marry the Joule heating effect and ultrahigh thermal conductivity in graphene with the thermo-optical effect in silicon. In this article, we employ a hybrid structure with graphene coated on a ring resonator to fabricate a thermo-optic modulator. Its modulation depth and 10%- 90% rise time(90%- 10% fall time) are 7 dB and 750 ns(800 ns), respectively. In addition, the active area of the device is as low as 10 μm2. Compared with the conventional thermo-optic modulators, the device performance is much improved and the fabrication process is greatly simplified. Such a device will find application in wavelength filter and switching arrays.