All-integrated universal RF photonic spectral shaper

We demonstrate a microwave photonic spectral shaper in a silicon chip enabling distinct phase and amplitude modulation transformation. We show unprecedented RF filtering through monolithic integration of the spectral shaper with tunable ring resonators

Monolithically integrated active optical devices

Considerations relevant to the monolithic integration of optical detectors, lasers, and modulators with high speed amplifiers are discussed. Some design considerations for representative subsystems in the GaAs-AlGaAs and GaInAs-InP materials systems are described. Results of a detailed numerical design of an electro-optical birefringent filter for monolithic integration with a laser diode is described, and early experimental results on monolithic integration of broadband MESFET amplifiers with photoconductive detectors are reported

Nanolasers grown on silicon

Integration of optical interconnects with silicon-based electronics can address the growing limitations facing chip-scale data transport as microprocessors become progressively faster. However, material lattice mismatch and incompatible growth temperatures have fundamentally limited monolithic integration of lasers onto silicon substrates until now. Here, we use a novel growth scheme to overcome this roadblock and directly grow on-chip InGaAs nanopillar lasers, demonstrating the potency of bottom-up nano-optoelectronic integration. Unique helically-propagating cavity modes are employed to strongly confine light within subwavelength nanopillars despite low refractive index contrast between InGaAs and silicon. These modes thereby provide an avenue for engineering on-chip nanophotonic devices such as lasers. Nanopillar lasers are as-grown on silicon, offer tiny footprints and scalability, and are thereby particularly suited to high-density optoelectronics. They may ultimately form the basis of the missing monolithic light sources needed to bridge the existing gap between photonic and electronic circuits.Comment: submitted to Nature Photonic

Gallium Arsenide Monolithic Optoelectronic Circuits

The optical properties of GaAs make it a very useful material for the fabrication of optical emitters and detectors. GaAs also possesses electronic properties which allow the fabrication of high speed electronic devices which are superior to conventional silicon devices. Monolithic optoelectronic circuits are formed by the integration of optical and electronic devices on a single GaAs substrate. Integration of many devices is most easily accomplished on a semi-insulating (SI) sub-strate. Several laser structures have been fabricated on SI GaAs substrates. Some of these lasers have been integrated with Gunn diodes and with metal semiconductor field effect transistors (MESFETs). An integrated optical repeater has been demonstrated in which MESFETs are used for optical detection and electronic amplification, and a laser is used to regenerate the optical signal. Monolithic optoelectronic circuits have also been constructed on conducting substrates. A heterojunction bipolar transistor driver has been integrated with a laser on an n-type GaAs substrate

Monolithic Integration of a Plasmonic Sensor with CMOS Technology

Monolithic integration of nanophotonic sensors with CMOS detectors can transform the laboratory based nanophotonic sensors into practical devices with a range of applications in everyday life. In this work, by monolithically integrating an array of gold nanodiscs with the CMOS photodiode we have developed a compact and miniaturized nanophotonic sensor system having direct electrical read out. Doing so eliminates the need of expensive and bulky laboratory based optical spectrum analyzers used currently for measurements of nanophotonic sensor chips. The experimental optical sensitivity of the gold nanodiscs is measured to be 275 nm/RIU which translates to an electrical sensitivity of 5.4 V/RIU. This integration of nanophotonic sensors with the CMOS electronics has the potential to revolutionize personalized medical diagnostics similar to the way in which the CMOS technology has revolutionized the electronics industry

Space Power Amplification with Active Linearly Tapered Slot Antenna Array

A space power amplifier composed of active linearly tapered slot antennas (LTSA's) has been demonstrated and shown to have a gain of 30 dB at 20 GHz. In each of the antenna elements, a GaAs monolithic microwave integrated circuit (MMIC) three-stage power amplifier is integrated with two LTSA's. The LTSA and the MMIC power amplifier has a gain of 11 dB and power added efficiency of 14 percent respectively. The design is suitable for constructing a large array using monolithic integration techniques

A fully integrated high-Q Whispering-Gallery Wedge Resonator

Microresonator devices which posses ultra-high quality factors are essential for fundamental investigations and applications. Microsphere and microtoroid resonators support remarkably high Q's at optical frequencies, while planarity constrains preclude their integration into functional lightwave circuits. Conventional semiconductor processing can also be used to realize ultra-high-Q's with planar wedge-resonators. Still, their full integration with side-coupled dielectric waveguides remains an issue. Here we show the full monolithic integration of a wedge-resonator/waveguide vertically-coupled system on a silicon chip. In this approach the cavity and the waveguide lay in different planes. This permits to realize the shallow-angle wedge while the waveguide remains intact, allowing therefore to engineer a coupling of arbitrary strength between these two. The precise size-control and the robustness against post-processing operation due to its monolithic integration makes this system a prominent platform for industrial-scale integration of ultra-high-Q devices into planar lightwave chips.Comment: 6 pages, 4 figure

High-speed GaAlAs/GaAs p-i-n photodiode on a semi-insulating GaAs substrate

A high-speed, high-responsivity GaAlAs/GaAs p-i-n photodiode has been fabricated on a GaAs semi-insulating substrate. The 75-µm-diam photodiode has a 3-dB bandwidth of 2.5 GHz and responsivity of 0.45 A/W at 8400 Å (external quantum efficiency of 65%). The diode is suitable for monolithic integration with other optoelectronic devices

III/V-on-Si MQW lasers by using a novel photonic integration method of regrowth on a bonding template.

Silicon photonics is becoming a mainstream data-transmission solution for next-generation data centers, high-performance computers, and many emerging applications. The inefficiency of light emission in silicon still requires the integration of a III/V laser chip or optical gain materials onto a silicon substrate. A number of integration approaches, including flip-chip bonding, molecule or polymer wafer bonding, and monolithic III/V epitaxy, have been extensively explored in the past decade. Here, we demonstrate a novel photonic integration method of epitaxial regrowth of III/V on a III/V-on-SOI bonding template to realize heterogeneous lasers on silicon. This method decouples the correlated root causes, i.e., lattice, thermal, and domain mismatches, which are all responsible for a large number of detrimental dislocations in the heteroepitaxy process. The grown multi-quantum well vertical p-i-n diode laser structure shows a significantly low dislocation density of 9.5 × 104 cm-2, two orders of magnitude lower than the state-of-the-art conventional monolithic growth on Si. This low dislocation density would eliminate defect-induced laser lifetime concerns for practical applications. The fabricated lasers show room-temperature pulsed and continuous-wave lasing at 1.31 μm, with a minimal threshold current density of 813 A/cm2. This generic concept can be applied to other material systems to provide higher integration density, more functionalities and lower total cost for photonics as well as microelectronics, MEMS, and many other applications