Zheng Wang

Chinese Academy of Sciences | CAS · State Key Laboratory of Materials for Integrated Circuits

Subwavelength grating waveguide-based micro-ring resonators (SWGMRs) are a promising platform for research in light–matter interaction. However, it is extremely difficult to achieve small radius SWGMR devices (e.g., 5 μm) with satisfying quality factors (e.g., ∼ 10,000 ). One major issue is the large bend loss of small radius SWGMRs. In this work,...

To detect biochemicals with ultra-high sensitivity, efficiency, reproducibility and specificity has been the Holy Grail in the development of nanosensors. In this work, we report an innovative type of photonic-plasmonic hybrid Raman nanosensors integrated with electrokinetic manipulation by rational design, which offers dual mechanisms that enhance...

The exponential growth of global data traffic is driven by the unprecedented digitalization of the world. To meet the demands of next‐generation high‐capacity data communication systems, innovative solutions are required. Silicon photonics has gained significant attention due to its ability to integrate multiple core functions of optical interconne...

This paper presents an experimental and theoretical investigation of a graphene-integrated electro-absorption modulator (EAM) based on a slot waveguide. Due to the enhanced light-matter interaction of graphene, the device exhibits an impressive modulation efficiency (0.038 dBµm⁻¹V⁻¹) and bandwidth (≈ 16 GHz). Starting from these results, we carried...

Since their first demonstration, graphene-based silicon waveguide modulators have evolved towards very attractive devices for adoption in future optical interconnects. In this paper, we first review state-of-the-art for graphene-based intensity modulators. Two important device configurations are considered: one using a single graphene layer, biased...

We experimentally demonstrated >10 dB extinction ratio (ER) at 4 V pp with a 50µm-long double-layer graphene electro-absorption modulator (DLG EAM) integrated on a silicon slot waveguide. Both the modulation depth (0.2dB/µm) and efficiency (0.070 dBV ⁻¹ µm ⁻¹ ) exceed state-of-art.

Generating optical combs in a small form factor is of utmost importance for a wide range of applications such as datacom, LIDAR, and spectroscopy. Electrically powered mode-locked diode lasers provide combs with a high conversion efficiency, while simultaneously allowing for a dense spectrum of lines. In recent years, a number of integrated chip sc...

III-V opto-electronic devices (photodiodes, etched facet lasers) are micro-transfer-printed onto silicon waveguide circuits. An alignment-tolerant interface for evanescently-coupled devices is proposed enabling III-V/Si heterogeneously integrated PICs using micro-transfer-printing.

As VLSI technology scales to deep sub-micron, optical interconnect becomes an attractive alternative for on-chip communication. The traditional optical routing works mainly optimize the path loss, and few works explicitly exploit the optical-electrical co-design of on-chip interconnects. To overcome these limitations, we present an efficient framew...

The past several decades have witnessed the gradual transition from electrical to optical interconnects, ranging from long-haul telecommunication to chip-to-chip interconnects. As one type of key component in integrated optical interconnect and high-performance computing, optical modulators have been well developed these past few years, including u...

Due to the projected saturation of Moore’s law, as well as the drastically increasing trend of bandwidth with lower power consumption, silicon photonics has emerged as one of the most promising alternatives that has attracted a lasting interest due to the accessibility and maturity of ultra-compact passive and active integrated photonic components....

We experimentally demonstrate a two-bit thermal-optic ripple-carry full adder based on microdisk resonators in silicon photonics with the advantages of large bandwidth, low power consumption, and high scalability, paving the way to future optical computing.

All-optical switches have been considered as a promising solution to overcome the fundamental speed limit of the current electronic switches. However, the lack of a suitable third-order nonlinear material greatly hinders the development of this technology. Here we report the observation of ultrahigh third-order nonlinearity about 0.45 cm²/GW in gra...

To detect biochemicals with ultra-high sensitivity, efficiency, reproducibility and specificity has been the Holy Grail in the development of nanosensors. In this work, we report an innovative type of photonic-plasmonic hybrid Raman nanosensors integrated with electrokinetic manipulation by rational design, which offers dual mechanisms that enhance...

We propose a ripple-carry electro-optic full adder using microring resonators, taking advantage of unique properties of light on chip. This proposed design with larger bandwidth and lower power consumption paves the way to future optical computing.

We report an optical switch based architecture for realizing optical computing. Numerical simulation has been performed to validate the architecture by adopting CMOS compatible PN depletion micro-ring resonator as the approach for optical switching.

Subwavelength grating (SWG) waveguide is an intriguing alternative to conventional optical waveguides due to the extra degree of freedom it offers in tuning a few important waveguide properties, such as dispersion and refractive index. Devices based on SWG waveguides have demonstrated impressive performances compared to conventional waveguides. How...

Subwavelength grating (SWG) waveguide is an intriguing alternative to conventional optical waveguides due to its freedom to tune a few important waveguide properties such as dispersion and refractive index. Devices based on SWG waveguide have demonstrated impressive performances compared to those of conventional waveguides. However, the large loss...

In recent decades, silicon photonics has attracted intensive research interest in optical communications due to its advantageous compact dimensions and high-volume manufacturability. Particularly, micro-ring resonators on silicon-oninsulator (SOI) platform have been widely exploited as a basic building block for a vast range of applications such as...

We report the design and experimental demonstration of high quality factor, trapezoidal shape subwavelength grating waveguide micro-ring resonators (SWGMRs). A 5 μm radius SWGMR with a quality factor as high as 11,500 has been demonstrated for the first time.

We report the design, simulation and experimental demonstration of low loss subwavelength grating waveguide (SWG) bends. With trapezoidal shape silicon pillars, the average insertion loss of a 5μm SWG waveguide bend is reduced drastically from 5.43dB to 1.10dB per 90°bend for quasi-TE polarization.

We experimentally demonstrate that resonances in a system of coupled photonic crystal microcavities can have higher quality factor (Q~15,000) than an uncoupled cavity (Q~4,000), which is critical for sensing applications. We study theoretically the origins of higher Q coupled photonic molecules.

We experimentally demonstrate 2-D photonic crystal slab-coupled plasmonic nanocapsules for surface enhanced Raman spectroscopy (SERS). A strong Raman signal enhancement can be unambiguously detected even with a low concentration 10 nM dye molecules.

Traditional silicon waveguides are defined by waveguide trenches on either side of the high-index silicon core that leads to fluid leakage orifices for over-layed microfluidic channels. Closing the orifices needs additional fabrication steps which may include oxide deposition and planarization. We experimentally demonstrated a new type of microflui...

A method for the dense integration of high sensitivity photonic crystal (PC) waveguide based biosensors is proposed and experimentally demonstrated on a silicon platform. By connecting an additional PC waveguide filter to a PC microcavity sensor in series, a transmission passband is created, containing the resonances of the PC microcavity for sensi...

Integrating photonic waveguide sensors with microfluidics is promising in achieving high-sensitivity and cost-effective biological and chemical sensing applications. One challenge in the integration is that an air gap would exist between the microfluidic channel and the photonic waveguide when the micro-channel and the waveguide intersect. The air...

We designed and fabricated guided-mode resonance (GMR) gratings on indium-tin-oxide (ITO) thin film to generate a significantly enhanced local electric field for surface-enhanced Raman scattering (SERS) spectroscopy. Ag nanoparticles (NPs) were self-assembled onto the surface of the grating, which can provide a large amount of "hot-spots" for SERS...

We experimentally demonstrated that multiplexing of PC sensors with different geometry can achieve a wide dynamic range covering 6 orders of magnitude with potential for 8 or more orders with suitable optimization.

We experimentally demonstrate a new type of micro-fluid channel design with crossing optical waveguides that not only block any gaps in the microfluidic channels in one fabrication step but also enable nearly lossless optical propagation in the primary waveguides on a chip

A photonic crystal (PC) waveguide based optical filter that enables dense integration of high sensitivity L55 PC microcavities for biosensor microarrays is demonstrated.

Searching for suitable platinum-free electrocatalysts toward novel iodine-free redox couples is of vital importance for further cost reduction and large-scale implementation of dye-sensitized solar cells (DSCs). Herein, cross-stacked superaligned carbon nanotube (CSCNT) sheets were incorporated as efficient economical cathodes in organic disulfide/...

Carbon nanotube (CNT) films, easily drawn from super-aligned CNT arrays with a large area and a good compatibility with semiconductor technology, have been used as light sensitive materials for infrared (IR) detection. A bolometric CNT detector made from one layer of super-aligned CNT film shows a 15.4% resistance change under 10 mW mm(-2) of IR il...