Largely chirped microwave waveform generation using a silicon-based on-chip optical spectral shaper

Author(s):  
Weifeng Zhang ◽  
Jiejun Zhang ◽  
Jianping Yao
Nanophotonics ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 2377-2385 ◽  
Author(s):  
Zhao Cheng ◽  
Xiaolong Zhu ◽  
Michael Galili ◽  
Lars Hagedorn Frandsen ◽  
Hao Hu ◽  
...  

AbstractGraphene has been widely used in silicon-based optical modulators for its ultra-broadband light absorption and ultrafast optoelectronic response. By incorporating graphene and slow-light silicon photonic crystal waveguide (PhCW), here we propose and experimentally demonstrate a unique double-layer graphene electro-absorption modulator in telecommunication applications. The modulator exhibits a modulation depth of 0.5 dB/μm with a bandwidth of 13.6 GHz, while graphene coverage length is only 1.2 μm in simulations. We also fabricated the graphene modulator on silicon platform, and the device achieved a modulation bandwidth at 12 GHz. The proposed graphene-PhCW modulator may have potentials in the applications of on-chip interconnections.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 239
Author(s):  
Yineng Wang ◽  
Xi Cao ◽  
Walter Messina ◽  
Anna Hogan ◽  
Justina Ugwah ◽  
...  

Capillary electrochromatography (CEC) is a separation technique that hybridizes liquid chromatography (LC) and capillary electrophoresis (CE). The selectivity offered by LC stationary phase results in rapid separations, high efficiency, high selectivity, minimal analyte and buffer consumption. Chip-based CE and CEC separation techniques are also gaining interest, as the microchip can provide precise on-chip control over the experiment. Capacitively coupled contactless conductivity detection (C4D) offers the contactless electrode configuration, and thus is not in contact with the solutions under investigation. This prevents contamination, so it can be easy to use as well as maintain. This study investigated a chip-based CE/CEC with C4D technique, including silicon-based microfluidic device fabrication processes with packaging, design and optimization. It also examined the compatibility of the silicon-based CEC microchip interfaced with C4D. In this paper, the authors demonstrated a nanofabrication technique for a novel microchip electrochromatography (MEC) device, whose capability is to be used as a mobile analytical equipment. This research investigated using samples of potassium ions, sodium ions and aspirin (acetylsalicylic acid).


2017 ◽  
Vol 38 (6) ◽  
pp. 065004
Author(s):  
Hansheng Wang ◽  
Weiliang He ◽  
Minghui Zhang ◽  
Lu Tanh

Author(s):  
Wei Xu ◽  
Hong Xue ◽  
Mark Bachman ◽  
G. P. Li

Microflow valving and regulating are two important functions for microfluidic systems for applications such as Lab-on-Chip. Although silicon based counterparts have been studied extensively, few good technologies exist for polymer based microvalves and regulators. In this paper, we present designs and methods for microvalve and microflow regulators that are readily integrated into polymer microfluidic devices. The technologies utilize “air-pocket” structures built into the sidewalls of the microchannels. When liquid is filled in such a channel, air is trapped in “air pocket” structures due to the hydrophobicity of the polymer. By creating a small thermal gradient between the fluid in the channel and the air in the pockets, one can controllably evaporate fluid into the air pocket where it condenses. This displaces air out of the pocket into the flow channel, increasing the resistance to flow. The air valve retreats to its original pocket when the temperature gradient is removed, thus allowing one to increase or decrease fluid flow at will. If the temperature gradient is maintained long enough, the air will completely block the channel, forming an irreversible valving of the flow. Therefore, the same device can be used as either a valve or flow-regulating device. Microfluidic prototypes were built and tested using this technology. The results show successful constant flow delivery as well as valve function. This novel vapor based microflow valve and regulator has advantages of low cost, simple design, and both ease of fabrication and integration.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Monica Bollani ◽  
Marco Salvalaglio ◽  
Abdennacer Benali ◽  
Mohammed Bouabdellaoui ◽  
Meher Naffouti ◽  
...  

AbstractLarge-scale, defect-free, micro- and nano-circuits with controlled inter-connections represent the nexus between electronic and photonic components. However, their fabrication over large scales often requires demanding procedures that are hardly scalable. Here we synthesize arrays of parallel ultra-long (up to 0.75 mm), monocrystalline, silicon-based nano-wires and complex, connected circuits exploiting low-resolution etching and annealing of thin silicon films on insulator. Phase field simulations reveal that crystal faceting and stabilization of the wires against breaking is due to surface energy anisotropy. Wires splitting, inter-connections and direction are independently managed by engineering the dewetting fronts and exploiting the spontaneous formation of kinks. Finally, we fabricate field-effect transistors with state-of-the-art trans-conductance and electron mobility. Beyond the first experimental evidence of controlled dewetting of patches featuring a record aspect ratio of $$\sim$$~1/60000 and self-assembled $$\sim$$~mm long nano-wires, our method constitutes a distinct and promising approach for the deterministic implementation of atomically-smooth, mono-crystalline electronic and photonic circuits.


Nanophotonics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 467-474 ◽  
Author(s):  
Wenhao Wu ◽  
Yu Yu ◽  
Wei Liu ◽  
Xinliang Zhang

AbstractPolarization measurement has been widely used in material characterization, medical diagnosis and remote sensing. However, existing commercial polarization analyzers are either bulky schemes or operate in non-real time. Recently, various polarization analyzers have been reported using metal metasurface structures, which require elaborate fabrication and additional detection devices. In this paper, a compact and fully integrated silicon polarization analyzer with a photonic crystal-like metastructure for polarization manipulation and four subsequent on-chip photodetectors for light-current conversion is proposed and demonstrated. The input polarization state can be retrieved instantly by calculating four output photocurrents. The proposed polarization analyzer is complementary metal oxide semiconductor-compatible, making it possible for mass production and easy integration with other silicon-based devices monolithically. Experimental verification is also performed for comparison with a commercial polarization analyzer, and deviations of the measured polarization angle are <±1.2%.


Photonics ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 13 ◽  
Author(s):  
Reza Maram ◽  
Saket Kaushal ◽  
José Azaña ◽  
Lawrence Chen

Multitude applications of photonic devices and technologies for the generation and manipulation of arbitrary and random microwave waveforms, at unprecedented processing speeds, have been proposed in the literature over the past three decades. This class of photonic applications for microwave engineering is known as microwave photonics (MWP). The vast capabilities of MWP have allowed the realization of key functionalities which are either highly complex or simply not possible in the microwave domain alone. Recently, this growing field has adopted the integrated photonics technologies to develop microwave photonic systems with enhanced robustness as well as with a significant reduction of size, cost, weight, and power consumption. In particular, silicon photonics technology is of great interest for this aim as it offers outstanding possibilities for integration of highly-complex active and passive photonic devices, permitting monolithic integration of MWP with high-speed silicon electronics. In this article, we present a review of recent work on MWP functions developed on the silicon platform. We particularly focus on newly reported designs for signal modulation, arbitrary waveform generation, filtering, true-time delay, phase shifting, beam steering, and frequency measurement.


2015 ◽  
Vol 1 (8) ◽  
pp. e1500257 ◽  
Author(s):  
Chuang Zhang ◽  
Chang-Ling Zou ◽  
Yan Zhao ◽  
Chun-Hua Dong ◽  
Cong Wei ◽  
...  

A photonic integrated circuit (PIC) is the optical analogy of an electronic loop in which photons are signal carriers with high transport speed and parallel processing capability. Besides the most frequently demonstrated silicon-based circuits, PICs require a variety of materials for light generation, processing, modulation, and detection. With their diversity and flexibility, organic molecular materials provide an alternative platform for photonics; however, the versatile fabrication of organic integrated circuits with the desired photonic performance remains a big challenge. The rapid development of flexible electronics has shown that a solution printing technique has considerable potential for the large-scale fabrication and integration of microsized/nanosized devices. We propose the idea of soft photonics and demonstrate the function-directed fabrication of high-quality organic photonic devices and circuits. We prepared size-tunable and reproducible polymer microring resonators on a wafer-scale transparent and flexible chip using a solution printing technique. The printed optical resonator showed a quality (Q) factor higher than 4 × 105, which is comparable to that of silicon-based resonators. The high material compatibility of this printed photonic chip enabled us to realize low-threshold microlasers by doping organic functional molecules into a typical photonic device. On an identical chip, this construction strategy allowed us to design a complex assembly of one-dimensional waveguide and resonator components for light signal filtering and optical storage toward the large-scale on-chip integration of microscopic photonic units. Thus, we have developed a scheme for soft photonic integration that may motivate further studies on organic photonic materials and devices.


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