scholarly journals Folded Heterogeneous Silicon and Lithium Niobate Mach–Zehnder Modulators with Low Drive Voltage

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 823
Author(s):  
Shihao Sun ◽  
Mengyue Xu ◽  
Mingbo He ◽  
Shengqian Gao ◽  
Xian Zhang ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Optical Networks ◽  
Transmission Lines ◽  
Optical Waveguides ◽  
Optical Loss ◽  
Optical Modulators ◽  
Drive Voltage ◽  
Half Wave Voltage ◽  
Half Wave ◽  
Overall Performance

Optical modulators were, are, and will continue to be the underpinning devices for optical transceivers at all levels of the optical networks. Recently, heterogeneously integrated silicon and lithium niobate (Si/LN) optical modulators have demonstrated attractive overall performance in terms of optical loss, drive voltage, and modulation bandwidth. However, due to the moderate Pockels coefficient of lithium niobate, the device length of the Si/LN modulator is still relatively long for low-drive-voltage operation. Here, we report a folded Si/LN Mach–Zehnder modulator consisting of meandering optical waveguides and meandering microwave transmission lines, whose device length is approximately two-fifths of the unfolded counterpart while maintaining the overall performance. The present devices feature a low half-wave voltage of 1.24 V, support data rates up to 128 gigabits per second, and show a device length of less than 9 mm.

The Compensation of Y Waveguide Temperature Drifts in FOG with the Thermal Resistor

2014 ◽  
Vol 924 ◽  
pp. 336-342 ◽  
Author(s):  
Ying Li Wang ◽  
Li Yong Ren ◽  
Jin Tao Xu ◽  
Jian Liang ◽  
Meng Hua Kang ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Fiber Optic ◽  
Driving Voltage ◽  
Fiber Optic Gyroscope ◽  
Temperature Drift ◽  
Thermal Resistor ◽  
Bias Drift ◽  
Half Wave Voltage ◽  
Half Wave ◽  
Environment Temperature

The lithium niobate integrated optical phase modulator (Y waveguide) is the key device in the digital closed-loop fiber optic gyroscope. However, the half-wave voltage of the lithium niobate changes with the environment temperature, which produces the phase bias drift and ultimately decreases the accuracy of FOG. In this manuscript, the thermal resistor is introduced in the amplification part in the driving circuits of Y waveguide. Due to the characteristic of the thermal resistor, the magnitude of driving voltage on Y waveguide changed with temperature to compensate the electro-optic effects temperature drift of the lithium niobate. This method was proved to improve the performance of fiber optic gyroscopes conveniently in experiment.

Methods for measuring the RF half-wave voltage of LiNbO3 optical modulators

2005 ◽  
Vol 46 (5) ◽  
pp. 440-443 ◽  
Author(s):  
Y. Di ◽  
P. Gardner ◽  
H. Ghafouri-Shiraz
Keyword(s):  
Optical Modulators ◽  
Half Wave Voltage ◽  
Half Wave

Polymers for Optical-Communications Device Fabrication-Optical Adhesives and Polyimide Waveguides-

1996 ◽  
Vol 444 ◽  
Author(s):  
T. Maruno
Keyword(s):  
Refractive Index ◽  
Optical Communications ◽  
Optical Waveguides ◽  
Near Infrared ◽  
Optical Loss ◽  
Epoxy Adhesive ◽  
Device Fabrication ◽  
Optical Modulators ◽  
Uv Curable ◽  
Fluorinated Polyimide

AbstractTwo types of novel organic materials have been specifically developed for the fabrication of optical-communications systems devices. One is a UV-curable durable epoxy adhesive featuring refractive index controllability, low shrinkage during curing, and a low heat-expansion coefficient. These optically transparent adhesives are refractive index controllable between 1.45 and 1.59, and have been successfully applied to many optical devices that require return losses of more than 40 dB. The precision adhesives show an extremely low volume shrinkage of less than 2% during curing. The submicron positioning accuracy of these adhesives allows the fabrication of highperformance laser-diode modules and optical modulators. The other type of material is a fluorinated polyimide (F-PI) for optical waveguides; it features high optical transparency from visible to near-infrared and good heat resistance. Buried optical waveguides fabricated from F-PI operate in a single mode. They also exhibit a low loss of less than 0.3 dB/cm at the wavelength of 1.3 μm, and are heat and moisture resistant: the increase in optical loss is less than 5% after heating at 300°C for lh or after exposure to 85% relative humidity at 85°C for 24h.

Wideband thin-film lithium niobate modulator with low half-wave-voltage length product

2021 ◽  
Vol 19 (6) ◽  
pp. 060016
Author(s):  
Xuecheng Liu ◽  
Bing Xiong ◽  
Changzheng Sun ◽  
Jian Wang ◽  
Zhibiao Hao ◽  
...  
Keyword(s):  
Thin Film ◽  
Lithium Niobate ◽  
Half Wave Voltage ◽  
Half Wave

scholarly journals Design and Optimization of Proton Exchanged Integrated Electro-Optic Modulators in X-Cut Lithium Niobate Thin Film

Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 549 ◽  
Author(s):  
Huangpu Han ◽  
Bingxi Xiang ◽  
Tao Lin ◽  
Guangyue Chai ◽  
Shuangchen Ruan
Keyword(s):  
Thin Film ◽  
Lithium Niobate ◽  
Power Distribution ◽  
Optical Power ◽  
Single Mode ◽  
Design Parameters ◽  
Design And Optimization ◽  
Half Wave Voltage ◽  
Half Wave ◽  
Electro Optic

In this study, we designed, simulated, and optimized proton exchanged integrated Mach-Zehnder modulators in a 0.5-μm-thick x-cut lithium niobate thin film. The single-mode conditions, the mode distributions, and the optical power distribution of the lithium niobate channel waveguides are discussed and compared in this study. The design parameters of the Y-branch and the separation distances between the electrodes were optimized. The relationship between the half-wave voltage length production of the electro-optic modulators and the thickness of the proton exchanged region was studied.

scholarly journals Novel High-Efficiency High Step-Up DC–DC Converter with Soft Switching and Low Component Voltage Stress for Photovoltaic System

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1112
Author(s):  
Yu-En Wu ◽  
Jyun-Wei Wang
Keyword(s):  
High Voltage ◽  
Output Voltage ◽  
High Efficiency ◽  
Low Voltage ◽  
Leakage Inductance ◽  
Power Switch ◽  
Half Wave Voltage ◽  
Half Wave ◽  
Voltage Stress ◽  
Voltage Doubler

This study developed a novel, high-efficiency, high step-up DC–DC converter for photovoltaic (PV) systems. The converter can step-up the low output voltage of PV modules to the voltage level of the inverter and is used to feed into the grid. The converter can achieve a high step-up voltage through its architecture consisting of a three-winding coupled inductor common iron core on the low-voltage side and a half-wave voltage doubler circuit on the high-voltage side. The leakage inductance energy generated by the coupling inductor during the conversion process can be recovered by the capacitor on the low-voltage side to reduce the voltage surge on the power switch, which gives the power switch of the circuit a soft-switching effect. In addition, the half-wave voltage doubler circuit on the high-voltage side can recover the leakage inductance energy of the tertiary side and increase the output voltage. The advantages of the circuit are low loss, high efficiency, high conversion ratio, and low component voltage stress. Finally, a 500-W high step-up converter was experimentally tested to verify the feasibility and practicability of the proposed architecture. The results revealed that the highest efficiency of the circuit is 98%.

scholarly journals All-optical dynamic tuning of local excitonic emission of monolayer MoS2 by integration with Ge2Sb2Te5

Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2351-2359
Author(s):  
Hao Ouyang ◽  
Haitao Chen ◽  
Yuxiang Tang ◽  
Jun Zhang ◽  
Chenxi Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Phase Change ◽  
Optical Networks ◽  
Dominant Role ◽  
Laser Pulses ◽  
Coulomb Interactions ◽  
Optical Modulators ◽  
Dynamic Tuning ◽  
All Optical ◽  
Excitonic Emission

AbstractStrong quantum confinement and coulomb interactions induce tightly bound quasiparticles such as excitons and trions in an atomically thin layer of transitional metal dichalcogenides (TMDs), which play a dominant role in determining their intriguing optoelectronic properties. Thus, controlling the excitonic properties is essential for the applications of TMD-based devices. Here, we demonstrate the all-optical tuning of the local excitonic emission from a monolayer MoS2 hybridized with phase-change material Ge2Sb2Te5 (GST) thin film. By applying pulsed laser with different power on the MoS2/GST heterostructure, the peak energies of the excitonic emission of MoS2 can be tuned up to 40 meV, and the exciton/trion intensity ratio can be tuned by at least one order of magnitude. Raman spectra and transient pump-probe measurements show that the tunability originated from the laser-induced phase change of the GST thin film with charge transferring from GST to the monolayer MoS2. The dynamic tuning of the excitonic emission was all done with localized laser pulses and could be scaled readily, which pave a new way of controlling the excitonic emission in TMDs. Our findings could be potentially used as all-optical modulators or switches in future optical networks.

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