Ultra-shallow junction electrodes in low-loss silicon micro-ring resonators
Bin-Bin Xu, Gabriele G. de Boo, Brett C. Johnson, Miloš Rančić, Alvaro Casas Bedoya, Blair Morrison, Jeffrey C. McCallum, Benjamin J. Eggleton, Matthew J. Sella… 展开作者
Bin-Bin Xu, Gabriele G. de Boo, Brett C. Johnson, Miloš Rančić, Alvaro Casas Bedoya, Blair Morrison, Jeffrey C. McCallum, Benjamin J. Eggleton, Matthew J. Sellars, Chunming Yin, Sven Rogge
Electrodes in close proximity to an active area of a device are required for sufficient electrical control. The integration of such electrodes into optical devices can be challenging since low optical losses must be retained to realise high quality operation. Here, we demonstrate that it is possible to place a metallic shallow phosphorus doped layer in a silicon micro-ring cavity that can function at cryogenic temperatures. We verify that the shallow doping layer affects the local refractive index while inducing minimal losses with quality factors up to 10$^5$. This demonstration opens up a pathway to the integration of an electronic device, such as a single-electron transistor, into an optical circuit on the same material platform.
In this paper, we present an electro-optical modulator made of two parallel nanoelectromechanical silicon nitride string resonators. These strings are covered with electrically connected gold electrodes and actuated either by Lorentz or electrostatic forces. The in-plane string vibrations modulate thewidth of the gap between the strings. The gold electrodes on both sides of the gap act as a mobile mirror that modulate the laser light that is focused in the middle of this gap. These electro-optical modulators can achieve an optical modulation depth of almost 100% for a driving voltage lower tha…
Mechanical resonators made with monolithic piezoelectric quartz crystals are promising for studying new physical phenomena. High mechanical quality factors ($Q$) exhibited by the mm-sized quartz resonators make them ideal for studying weak couplings or long timescales in the quantum regime. However, energy losses through mechanical supports pose a serious limiting factor for obtaining high quality factors. Here we investigate how the $Q$ of quartz resonators at deep cryogenic temperatures can be limited by several types of losses related to anchoring. We first introduce means to reduce the mec…
We report second harmonic generation from a titanium indiffused lithium niobate waveguide resonator device whose cavity length is locked to the fundamental pump laser using an on-chip phase modulator. The device remains locked for more than 5 minutes, producing more than 80\% of the initial second harmonic power. The stability of the system is seen to be limited by DC-drift, a known effect in many lithium niobate systems that include deposited electrodes. The presented device explores the suitability of waveguide resonators in this platform for use in larger integrated networks.
This work presents for the first time a flexible over-moded resonator (OMR) based on P(VDF-TrFE) thin films. The devices were manufactured on commercially available elastic substrate with inkjet-printed electrodes. The sensing copolymer films used in the devices were polarized by the corona method after electrode deposition. The main performance parameters of the component were then determined. The manufactured OMRs on P(VDF-TrFE) exhibited a linear variation of frequency versus temperature and a very large value of temperature coefficient of frequency (TCF > 1600 ppm/degrees C). These propert…
Acoustic wave resonators are promising for gravimetric biosensing. However, they generally suffer from strong acoustic radiation in liquid, which limits their quality factor and increases their frequency noise. This article presents an acoustic-radiation-free gravimetric biosensor based on a locally-resonant surface phononic crystal (SPC) consisting of periodic high aspect ratio electrodes to ad-dress the above issue. The acoustic wave generated in the SPC is slower than the sound wave in water, hence preventing acoustic propagation in the fluid and resulting in energy confinement near the ele…
We report a tunable optical filter based on phase change material $Ge_{2}Sb_{2}Te_{5}$ embedded in a silicon microring resonator. The high thermo-optic coefficient of $Ge_{2}Sb_{2}Te_{5}$ in amorphous phase enables tuning of resonance wavelength in broad range with a very small active volume. The low-loss indium-tin-oxide electrodes are employed to induce Joule heating in $Ge_{2}Sb_{2}Te_{5}$-Si active waveguide region. The electrically induced heating in the active region alters the effective refractive index of hybrid microring resulting in a wavelength tuning of 1.04 nm for an applied volta…
This abstract presents an aluminum nitride (AlN) piezoelectric actuator for tuning optical resonance modes of silicon nitride photonic resonators. The AlN actuator is fabricated on top of a thick silicon dioxide cladding that encapsulates the nitride resonator and waveguide. The PORT is defined by undercutting the cladding layer with a lateral silicon etch. It tunes the optical wavelength by 20pm on applying 60 V to the top electrode with a 0.5nA current draw. The thick oxide cladding preserves the resonator's loaded quality factor Q optical of 64,000 across the entire tuning range. The first …
We generalize the two-dimensional scalar differential equations for the thickness-extensional operating modes of thin film bulk acoustic wave resonators (FBARs) to include the effects of surface impedance so that the equations can be used to model sensors based on FBARs. A mass sensor is analyzed as an example to show the effectiveness of the equations obtained. The mass layer inducer frequency shifts are calculated. It is also found that the vibration may be confined under the driving electrode or the mass layer. These are fundamental to mass sensor design.
We demonstrate high-frequency (> 3 GHz), high quality factor radio frequency (RF) resonators in unreleased thin film gallium nitride (GaN) on sapphire and silicon carbide substrates by exploiting acoustic guided mode (Lamb wave) resonances. The associated energy trapping, due to mass loading from the gold electrodes, allows us to efficiently excite these resonances from a 50 $Ω$ input. The higher phase velocity, combined with lower electrode damping, enables high quality factors with moderate electrode pitch, and provides a viable route towards high-frequency piezoelectric devices. The GaN pla…
This letter presents a numerical investigation of acoustic modes propagating in an LiNbO$_3$/sapphire substrate under a periodic Al grating, demonstrating the occurrence of longitudinal leaky SAWs (LLSAWs) with a unique combination of very high velocities exceeding 10 000 m/s, an electromechanical coupling coefficients of 4.5%, and negligible leakage into the substrate. The leakage was suppressed by optimizing the LiNbO$_3$ (LN) plate and Al electrode thickness. Compared with conventional SAW substrates, the LN/sapphire substrate offers 2- to 2.5-fold higher frequencies for periodic electrode …
Complementary-polarity double-layer LiTaO3 resonators for symmetry-selective SH2 excitation with ultrahigh electromechanical coupling (kt^2 = 25.7%)
National Laboratory of Solid-State Microstructures & Department of Materials Science and Engineering, Nanjing University（南京大学固态微结构国家重点实验室及材料科学与工程系）；Collaborative Innovation Center of Advanced Microstructures, Nanjing University（南京大学先进微结构协同创新中心）；Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University（南京大学江苏省人工功能材料重点实验室）；School of Electronic Science and Engineering, Nanjing University（南京大学电子科学与工程学院）
To realize efficient nonlinear metamaterials, we investigate a method for enhancing the local electric field in a metamolecule composed of two radiatively coupled cut-wire resonators where resonance of the cut-wire resonators and low-group-velocity propagation of an incident electromagnetic wave simultaneously occur. Numerical analysis shows that the local electric field in the metamolecule can be enhanced by decreasing the electrode size and the gap of the capacitor structure of the cut-wire resonators while keeping the equivalent electrical circuit parameters of the metamolecule constant. We…
A fabrication process is developed to grow c-axis textured aluminum nitride (AlN) films on the sidewall of single crystal silicon (Si) micro-fins to realize fin bulk acoustic wave resonators (FinBAR). FinBARs enable ultra-dense integration of high quality-factor (Q) resonators and low-loss filters on a small chip footprint and provide extreme lithographical frequency scalability over ultra- and super-high-frequency regimes. Si micro-fins with large aspect ratio are patterned and their sidewall surfaces are atomically smoothened. The reactive magnetron sputtering AlN deposition is engineered to…
Integrated photonics has enabled signal synthesis, modulation and conversion using photonic integrated circuits (PIC). Many materials have been developed, among which silicon nitride (Si$_3$N$_4$) has emerged as a leading platform particularly for nonlinear photonics. Low-loss Si$_3$N$_4$ PIC has been widely used for frequency comb generation, narrow-linewidth lasers, microwave photonics, photonic computing networks, and even surface-electrode ion traps. Yet, among all demonstrated functionalities for Si$_3$N$_4$ integrated photonics, optical non-reciprocal devices, such as isolators and circu…
