Silicon-Organic Hybrid Electro-Optic Modulator and Microwave Photonics Signal Processing Applications.

Electro-optic modulator (EOM) is one of the key devices of high-speed optical fiber communication systems and ultra-wideband microwave photonic systems. Silicon-organic hybrid (SOH) integration platform combines the advantages of silicon photonics and organic materials, providing a high electro-optic effect and compact structure for photonic integrated devices. In this paper, we present an SOH-integrated EOM with comprehensive investigation of EOM structure design, silicon waveguide fabrication with Slot structure, on-chip poling of organic electro-optic material, and characterization of EO modulation response.

Hybrid integrated SiN external cavity laser with high power and narrow linewidth.

We have designed and fabricated a hybrid integrated laser source with full C-band wavelength tunability and high-power output. The external cavity laser is composed of a gain chip and a dual micro-ring narrowband filter integrated on the silicon nitride photonic chip to achieve a wavelength tuning range of 55 nm and a SMSR higher than 50 dB. Through the integration of the semiconductor optical amplifier in the miniaturized package, the laser exhibits an output power of 220 mW and linewidth narrower than 8 kHz over the full C-band.

Rogue wave generation using a chaotic semiconductor laser with energy redistribution.

We demonstrate for the first time that optical rogue waves (RWs) can be generated using a chaotic semiconductor laser with energy redistribution. Chaotic dynamics are numerically generated using the rate equation model of an optically injected laser. The chaotic emission is then sent to an energy redistribution module (ERM) that consists of a temporal phase modulation and a dispersive propagation.

Multiband Signal Receiver by Using an Optical Bandpass Filter Integrated with a Photodetector on a Chip.

Photonic integration brings the promise of significant cost, power and space savings and propels the real applications of microwave photonic technology. In this paper, a multiband radio frequency (RF) signal simultaneous receiver using an optical bandpass filter (OBPF) integrated with a photodetector (PD) on a chip is proposed, which was experimentally demonstrated. The OBPF was composed of ring-assisted Mach-Zehnder interferometer with a periodical bandpass response featuring a box-like spectral shape.

Au nanoparticles as label-free competitive reporters for sensitivity enhanced fiber-optic SPR heparin sensor.

A label-free Au NPs-enhanced surface plasmon resonance (SPR) sensor was developed for the ultrasensitive detection of heparin based on competitive adsorption behavior of heparin and Au NPs on the poly (dimethyl-diallylammonium chloride) (PDDA)-modified optical fiber surface and the corresponding change in the resonance wavelength of SPR. Due to the high affinity between heparin and PDDA, the present senor shows good analytical performance with respect to heparin detection. Two obvious advantages of the proposed heparin sensor over other reported methods are: its much wider linear concentration range (10-10 g/mL) and lower limit of detection (0.

Recent Progress of Imprinted Polymer Photonic Waveguide Devices and Applications.

Polymers are promising materials for fabricating photonic integrated waveguide devices. Versatile functional devices can be manufactured using a simple process, with low cost and potential mass-manufacturing. This paper reviews the recent progress of polymer photonic integrated devices fabricated using the UV imprinting technique.

Mercaptopyridine-Functionalized Gold Nanoparticles for Fiber-Optic Surface Plasmon Resonance Hg Sensing.

As a highly toxic heavy metal ion, divalent mercuric ion (Hg) is one of the most widely diffused and hazardous environmental pollutants. In this work, a simple, portable, and inexpensive fiber-optic sensor based on surface plasmon resonance (SPR) effect was developed for Hg detection, which takes advantage of 4-mercaptopyridine (4-MPY)-functionalized Au nanoparticles (Au NPs/4-MPY) as a signal amplification tag. Based on the coordination between Hg and nitrogen in the pyridine moiety, we developed the sensor by self-assembling 4-MPY on Au film surfaces to capture Hg and then introducing Au NPs/4-MPY to generate a plasmonic coupling structure with the configuration of nanoparticle-on-mirror.

Tilted Fiber Bragg Grating Sensor Using Chemical Plating of a Palladium Membrane for the Detection of Hydrogen Leakage.

A tilted fiber Bragg grating (TFBG) hydrogen sensor coated with a palladium (Pd) membrane by the electroless plating method is proposed in this paper. A uniform layer of Pd metal is fabricated in aqueous solutions by the chemical coating method, which is used as the sensitive element to detect the change of the surrounding refractive index (SRI) caused by hydrogen absorption. The change in SRI causes an unsynchronized change of the cladding modes and the Bragg peak in the TFBG transmission spectrum, thereby eliminating the cross-sensitivity due to membrane expansion and is able to simultaneously monitor the presence of cracks in the pipe, as well as the hydrogen leakage.

Fiber-optic surface plasmon resonance glucose sensor enhanced with phenylboronic acid modified Au nanoparticles.

A highly sensitive surface plasmon resonance (SPR) sensor is reported for glucose detection using self-assembled p-mercaptophenylboronic acid (PMBA) monolayer on Au coated optical fibers. The cis-diol group of saccharides, such as for glucose, interacted with the self-assembled PMBA monolayers on the optical fibers, but the low molecular mass of glucose is insufficient for measuring a significant shift in SPR wavelength. The response for glucose was thus enhanced with Au nanoparticles (Au NPs) modified with 2-aminoethanethiol (AET) and PMBA.

RF signal detection by a tunable optoelectronic oscillator based on a PS-FBG.

Low-power radio frequency (RF) signal detection is highly desirable for many applications, ranging from wireless communication to radar systems. A tunable optoelectronic oscillator (OEO) based on a phase-shifted fiber Bragg grating for detecting low-power RF signals is proposed and experimentally demonstrated. When the frequency of the input RF signal is matched with the potential oscillation mode of the OEO, it is detected and amplified.

Rapid Covalent Immobilization of Proteins by Phenol-Based Photochemical Cross-Linking.

A strategy for photoinduced covalent immobilization of proteins on phenol-functionalized surfaces is described. Under visible light irradiation, the reaction can be completed within seconds at ambient temperature, with high yields in aqueous solution of physiological conditions. Protein immobilization is based on a ruthenium-catalyzed radical cross-linking reaction between proteins and phenol-modified surfaces, and the process has proven mild enough for lipase, Staphylococcus aureus protein A, and streptavidin to preserve their bioactivity.

Simultaneous even- and third-order distortion suppression in a microwave photonic link based on orthogonal polarization modulation, balanced detection, and optical sideband filtering.

A microwave photonic link (MPL) with simultaneous suppression of the even-order and third-order distortions using a polarization modulator (PolM), an optical bandpass filter (OBPF), and a balanced photodetector (BPD) is proposed and experimentally demonstrated. The even-order distortions are suppressed by utilizing orthogonal polarization modulation based on the PolM and balanced differential detection based on the BPD. The third-order distortions (IMD3) are suppressed by optimizing the spectral response of the OBPF with an optimal power ratio between the optical carrier and the sidebands of the phase-modulated signals from the PolM.

Organic silicone sol-gel polymer as a noncovalent carrier of receptor proteins for label-free optical biosensor application.

Optical biosensing techniques have become of key importance for label-free monitoring of biomolecular interactions in the current proteomics era. Together with an increasing emphasis on high-throughput applications in functional proteomics and drug discovery, there has been demand for facile and generally applicable methods for the immobilization of a wide range of receptor proteins. Here, we developed a polymer platform for microring resonator biosensors, which allows the immobilization of receptor proteins on the surface of waveguide directly without any additional modification.

Athermal arrayed waveguide gratings in silicon-on-insulator by overlaying a polymer cladding on narrowed arrayed waveguides.

Athermal arrayed waveguide gratings (AWGs) in silicon-on-insulator (SOI) are experimentally demonstrated for the first time to our knowledge. By using narrowed arrayed waveguides, and then overlaying a polymer layer, the wavelength temperature dependence of the AWGs is successfully reduced to -1.5 pm/°C, which is more than 1 order of magnitude less than that of normal SOI AWGs.

Athermal Silicon-on-insulator ring resonators by overlaying a polymer cladding on narrowed waveguides.

Athermal silicon ring resonators are experimentally demonstrated by overlaying a polymer cladding on narrowed silicon wires. The ideal width to achieve athermal condition for the TE mode of 220 nm-height SOI waveguides is found to be around 350 nm. After overlaying a polymer layer, the wavelength temperature dependence of the silicon ring resonator is reduced to less than 5 pm/degrees C, almost eleven times less than that of normal silicon waveguides.