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An integrated volatile organic compounds (VOC) sensor based on silicon photonic ring resonator system is presented in this paper. A thin absorption layer is coated on the silicon surface required to selectively trap the target gas and response as refractive index change. This acts as the main sensing unit, which subsequently affect the resonance peak position. The relative high sensitivity (1.7 pm/...
This paper proposes a novel evaluation method for MEMS gyroscopes' packaging reliability. Based on the principles of thermodynamics and hydromechanics, the relationships among quality factors, air pressure, and gas number, as well as degradation models of them, are deducted for the first time. Experimental tests demonstrate that the relationships between the reciprocals of the two-mode quality factors...
We demonstrate a novel way to control the coupling rate in coupled ring resonators by controlling the relative position of the nanowires between the two cavities to modulate the resonance frequencies. A new system is presented and experimental results show that by tuning the coupling rate, the coupled ring resonators can be stimulated at the same time due to the same resonance frequency. This study...
An on-chip refractive index (RI) sensor with high sensitivity and large measurement range is demonstrated. The sensing scheme presented here is based on Mach-Zehnder interferometer configuration built on an SOI wafer. The measured wavelength sensitivity reaches 3498.6 nm/RIU (TE-mode). Meanwhile, according to the period changes of interference patterns, the measured period sensitivities are 20.4 nm/RIU...
This paper demonstrates the optically induced self-excited relaxation oscillation in a silicon ring resonator for the first time. The observed thermo-optomechanical oscillation has a unique waveform with fast oscillation period close to 16 ns and slow oscillation period approximately 167 ns. The ultra-fast oscillation period can be well used in optical switch and optical memory elements. Particularly,...
This paper reports a NEMS spectrometer-on-a-chip, which integrates fiber-waveguide coupler and photo detector on a single silicon chip. Spectrometer based on Fourier transform, for the first time, has been miniaturized into a waveguide based silicon photonic chip. The on-chip spectrometer is fabricated by nano-silicon-photonic fabrication processes. It also eliminates moving parts and confine light...
Continuous separation of nano-sized molecules has great importance in biomedical applications. This paper represents a near-field optical approach to separate nanoparticles using speckle patterns. Near-field random light patterns (speckle pattern) are generated by the repeated coupling and interference of light in nano-waveguide arrays. The movements of 2-µm and 0.5-µm particles are studied under...
A tunable flat lens is demonstrated based on reconfigurable metasurface, which is realized via changing the phase gradient of the metasurface in sub-wavelength level. The sub-wavelength metamolecules are formed by enclosing a liquid metal plug within microfluidic cavities, which can be tuned by changing the geometry of the metamolecules. The tunable flat lens is consisted of soft material with controllable...
We experimentally demonstrate a silicon nano-wire actuator with a nano-scale resolution and tunable actuation range. The nano-scale resolution is obtained through implementing different control regulations, including coarse tuning by the electrostatic force and precision tuning by the optical force. More specially, the optical force enabled silicon nano-wire actuator can break the classical NEMS 1/3...
This paper reports a novel all-optical light tracker by taking advantage of the optomechanical modulation. The optical force generated by a light can be used to control another light without relying on the traditional nonlinear material. Particularly, the all-optical modulation can transfer the information in a signal light into another tracking light without resorting to electro-optical converting...
This paper reports a NEMS integrated photonic system, which integrate tunable laser, optical cross correct and variable optical attenuators. The NEMS integrated photonic system is fabricated with nano-silicon-photonic fabrication technology to integrate various functions in a single silicon photonic circuit chip. The high light-confinement capability of the nano-silicon waveguides guarantees superior...
This paper presents a compact silicon-photonic based optical cross connect (OXC) driven by the optical gradient force. Each switch element consists of a waveguide-crossing-coupled micro-ring resonator and a suspended arc. The device is fabricated with a standard CMOS compatible process using deep-UV 248-nm lithography with a double-etch technique. A switching time of 0.24 µs is experimentally demonstrated...
We develop a miniaturized electrostatically tunable optomechanical oscillator, whose frequencies can be electrostatically tuned by as much as 10%. By taking advantage of the optical and the electrical spring, the oscillator achieves a high tuning sensitivity without resorting to mechanical tension. Particularly, the high-Q optical cavity greatly enhances the system sensitivity, making it extremely...
This paper reports an on chip nano-optomechanical SRAM, which is integrated with light modulation system on a single silicon chip. In particular, a doubly-clamped silicon beam shows bistability due to the non-linear optical gradient force generated from a ring resonator. The memory states are assigned with two stable deformation positions, which can be switched by modulating the control light's power...
This paper reports a Nanoelectromechanical System (NEMS) Variable Optical Attenuator (VOA) driven by the optical gradient force. The VOA is realized via a waveguide based directional coupler. The gap in the directional coupler is controlled via an optical force driven actuator. The doubly-clamped silicon beam actuator is controlled by tuning the wavelength of control light. The signal light can be...
In this paper, a tunable THz lens array based on reconfigurable metamaterials is reported. The metamaterial consists with 40 × 40 liquid metal microdroplets, in which the shape is tuned under different air pressures. The droplets are formed by injecting the liquid mercury into a pre-designed microchannel network and arranged to focus incident THz wave. The focus spot size can be tuned with different...
This paper reports an integrated tunable laser using nano-silicon-photonic circuits. In particular, all the necessary optical functions in an external cavity laser system, including the beam transmission, coupling, filtering and reflection, are realized using waveguide-based circuits. The high light-confinement capability of the nano-silicon waveguides avoids high optical loss in free-space as suffered...
In this work, we use ballistic quantum transport in a III-nitride to realize room temperature negative differential resistance (NDR) in a GaN-based Tunneling Hot Electron Transistor. The results showed reproducible double-sweep characteristics, with peak-to-valley ratio (PVCR) of 7.2 and peak current density (PCD) about 143 A/cm2. This is the first report of repeatable room temperature negative differential...
We report N-polar GaN-based tunneling hot electron amplifier transistors (THETA) with common-emitter modulation, ac current gain up to 1.35 operating at collector current density ∼50 kA/cm2, which are highest values reported to date in GaN-based hot electron transistors. Achieving higher frequency operation in the III-nitride system requires an alternative to highly-scaled GaN-based HEMTs whose transconductance...
This paper presents a digital closed loop control method for the sense mode of a mode-matching MEMS vibratory gyroscope. The sense closed loop system reported in our previous work is relatively complex and unreliable due to the existence of notch filter. In this work, a more simple and robust control system is realized with the help of mode-matching control. With a tuning voltage automatically applied...
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