Low Power Silicon Electro-Optic Micro-Switch

0300387lipson1.3和1.55微米光纤通信波长的硅基光电开关和调制器，用于光纤到家庭互连和局域网（LAN），提供了使用双极或互补金属氧化物半导体（CMOS）技术在硅衬底上集成光学元件和先进电子器件的可能性。然而，大多数提出的硅电光（E-O）开关需要较长的相互作用距离和高驱动功率才能获得显著的调制深度。为了实现高水平的集成和小型化，长交互长度是不可取的。高电功率可引起竞争性热光学效应。PI提出了一种新型的微米级平面硅电光开关，具有低功耗和高调制深度。该器件基于平面法布里-珀罗（F-P）微腔。利用自由载流子等离子体色散效应[1,2]，利用侧向p-i-n二极管调制腔区的折射率。光场和注入的载流子都被强烈地限制在微腔中，使用高折射率对比Si/SiO2分布braggreflector （DBR）和沟槽隔离。光约束使得结构尺寸小，调制深度高。载流子约束是器件低功耗的原因。pi的初步计算表明，在25微瓦的功率驱动下，20微米长的器件可以具有80%的调制深度。据他们所知，这相当于第一个实用的硅集成光子有源器件。这种新型有源器件将作为有源片上硅器件的构建块。这些器件包括可调谐滤波器、可调谐光栅、调制器、开关、自适应耦合器等。芯片上的全光学系统可能成为现实，廉价、紧凑的有源和无源设备可以集成在芯片上，并以单片方式生长。

0300387LipsonSilicon-based optoelectronic switches and modulators at 1.3 and 1.55-um fiber-opticcommunications-wavelengths for fiber-to-home interconnects and local areanetworks (LAN) offer the possibility of integrating optical elements and advancedelectronics on a silicon substrate using bipolar or complementary metal-oxidesemiconductor (CMOS) technology. Most of the proposed Si electro-optic (E-O)switches, however, require long interaction distance and high drive powers for obtaininga significant modulation depth. Long interaction lengths are undesirable in order toachieve high levels of integration and miniaturization. High electrical powers may inducecompeting thermo-optic effects.The PI proposes a new class of micrometer-size planar Si electro-optic switches withlow power consumption and high modulation depth.The device is based on a planar Fabry-Perot (F-P) microcavity. Free-carrierplasma dispersion effect [1,2] is used to modulate the refractive index of the cavity regionby using a lateral p-i-n diode. Both optical field and injected carriers are stronglyconfined in the microcavity using high-index-contrast Si/SiO2 distributed Braggreflectors (DBR) and trench isolation. The optical confinement accounts for the smallsize of the structure and its high modulation depth. The carrier confinement accounts forthe device low power consumption.The PIs preliminary calculations show that a 20-micron long device can have 80%modulation depth under 25 microwatt power drives. To the best of their knowledge thiscorresponds to the first practical Si integrated photonic active device.This new class of active devices will function as a building block for active on-chipSi devices. These devices include tunable filters, tunable grating, modulators,switches, adaptive couplers among others. All-optical systems on a chip could become areality where inexpensive, compact active and passive devices could be integrated andmonolithically grown on a chip.