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We review recent progress on the application of long-range surface plasmon-polariton waveguide biosensors for disease detection. The biosensors are constructed from metal stripe waveguides cladded in Cytop with etched microfluidic channels to expose the stripe surface to the sensing fluid. The waveguides support long-range surface plasmons in integrated optics geometries when excited in an end-fire...
We have proposed and developed array-antenna-electrode LiNbO3 modulators operating in the millimeter-wave frequency band. In this paper, high-antenna-gain structures for up-links in wireless communication systems are discussed.
This paper discusses the challenges towards the realization of the integrated microwave photonic beamformer based on hybrid integration between InP and TriPleX Si3N4/SiO2.
We demonstrate a microwave photonic phased array antenna concept capable of symbol-by-symbol steering at symbol rates of 10 GBd. Such a system may increase mobile network capacity and reach by spatially addressing individual users.
We demonstrate a frequency-domain modulation spectroscopy system in the terahertz (THz) range based on the self-heterodyne technique to enhance the sensitivity of the small spectral change measurement. To evaluate the effectiveness of our system, we measured absorption of the THz wave caused by photo-induced free carriers generated in a high-resistive (4000 Ωcm) Si substrate. The 400-μm-thick Si substrate...
The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is a Chinese mega-science project funded by the National Development and Reform Commission (NDRC). The National Astronomical Observatories of China (NAOC) is in charge of its construction and the subsequent operation. Upon its expected completion in September of 2016, FAST will surpass the 300-meter Arecibo and the 100-meter GBT in terms...
This paper summarizes design approaches and recent experimental results of radio-frequency photodetectors and modulators for use in millimeter-wave analog photonic applications.
An array of GaAs/InGaAs/AlGaAs field-effect transistors with an asymmetric T-gate in each transistor and floating electrodes was fabricated on a single chip and tested as a detector of terahertz (THz) radiation. Principle of detection was based on excitation of plasma oscillations in the common electron channel of the FETs array. Strong terahertz photovoltaic response was demonstrated without any...
We present ultra-low phase noise microwave generation based on a photonics oscillator. By using an ultra-narrow linewidth continuous-wave laser stabilized on a high-finesse optical cavity as a frequency reference, an optical frequency comb as an optical-to-microwave frequency divider and a photodiode for optical-to-electrical conversion, a 9.6 GHz carrier frequency signal has been generated with residual...
Using a gain saturated SOA as a high-pass filter, we reduce the intensity noise of a hybrid III-V/Silicon laser by 8 dB around the relaxation oscillation frequency and up to 12dB around 100MHz leading to a Relative Intensity Noise (RIN) below −145 dB/Hz from 100 MHz to 20 GHz.
A racetrack-based modulator of increased linearity for optical links is presented and analyzed. The modulator is referred to as FLAME — Finer Linearity Amplitude Modulation Element. Linearity is improved via the introduction of a Double Injection approach. Large spurious-free-dynamic-range (SFDR) of 132dB∗Hz4/5 can thus be theoretically obtained. The FLAME is studied for silicon photonics and requires...
This paper demonstrates experimentally the distribution of radio-over-fiber (RoF) signals using orbital angular momentum (OAM) of light over standard OM4 multimode fiber (MMF) at 850 nm wavelength. Five independent OAM modes are used to convey RoF signals in the microwave regime showing robust performance and therefore opening new prospects for enhancing the capacity of MMF based RoF Links.
To detect small debris on the airport surface, the optically-connected distributed-type 96 GHz millimeter-wave radar system, which is based on radio-over-fiber (RoF) technology and an optical fiber network, has been proposed and developed. Such foreign object debris (FOD) is required to be removed immediately. The distributed-type radar system enables the improvement of both the FOD detection and...
A fully coherent dual band radar system based on a single photonic-assisted transceiver is presented and detailed. The proposed architecture allows simultaneous generation and detection of radar signals in the S- and X-band. The sharing of a single transceiver for both the frequency bands provides a perfect coherence among the generated waveforms, allowing improved data fusion techniques. In field...
We designed and fabricated a Silicon Nitride (Si3N4) photonic integrated circuit targeting wideband two-dimensional radio beamforming from 20–40 GHz for satellite communications. Continuous true time delay tunability is achieved by using thermo-optic phase shifters in a 2-port optical ring resonator. Scanning angles up to 20° and true time delay bandwidth up to 14 GHz are realized while tuning into...
Linear frequency-modulated (LFM) waveforms can be photonically generated by introducing a parabolic phase difference to two phase-correlated optical wavelengths followed by optical heterodyning, but the maximal achievable time-bandwidth product (TBWP) is limited by the modulation index of the electro-optic modulator, which is independent of the bandwidth or duration of the input signal. In this paper,...
Free-space indoor optical communication deploying pencil beams can offer ultra-high wireless capacity individually per user device. By means of 2D diffractive modules, such as a pair of crossed gratings, 2D steering of multiple beams by just tuning the wavelength of each beam can be achieved. The design aspects of an indoor system fed via an intelligent optical fiber backbone network are discussed...
We propose and experimentally demonstrate a photonic approach to generating a chirped microwave waveform with a large time-bandwidth product (TBWP) based on self-heterodyne technique. We use the chirp characteristic of a distributed feedback (DFB) laser (LD) to generate a frequency-modulated optical pulse, to directly modulate the LD using an injection current with a parabolic current shape that is...
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