Sensor analysis and initial assessment of detectable first hoof contacts and last break-overs as unique signal fluctuations for equine gait analysis.

The objective of the control study was to assess 2 prominent fluctuations in a single optical signal as being either a true first hoof contact or a last break-over based on descriptive measures. The study builds on initial findings from a preliminary investigation of the embedded-optical-base system's (EOBS) capabilities in signal capturing and feasibility as potential alternative to existing gait technologies, such as piezoelectric (e.g.

Two-axis tracking using translation stages for a lens-to-channel waveguide solar concentrator.

A two-axis tracking scheme designed for <250x concentration realized by a single-axis mechanical tracker and a translation stage is discussed. The translation stage is used for adjusting positions for seasonal sun movement. It has two-dimensional x-y tracking instead of horizontal movement x-only.

Design of a hybrid As₂S₃-Ti:LiNbO₃ optical waveguide for phase-matched difference frequency generation at mid-infrared.

Based on arsenic tri-sulfide films on titanium-diffused lithium niobate, we designed a hybrid optical waveguide for efficient mid-infrared emission by phase-matched difference frequency generation (DFG). The hybrid waveguide structure possesses a low-index magnesium fluoride buffer layer sandwiched between two high-index As(2)S(3) slabs, so that pump and signal waves are tightly confined by titanium-diffused waveguide while the DFG output idler wave at mid-infrared is confined by the whole hybrid waveguide structure. On a 1 mm-long hybrid waveguide pumped at 50 mW powers, a normalized power conversion efficiency of 20.

Design of a lens-to-channel waveguide system as a solar concentrator structure.

We present a lens-to-channel waveguide solar concentrator, where the lens array and the channel waveguide act as the primary and the secondary concentrator. Sunlight collected by the lens array is coupled into channel waveguides and exits from one end of the tapered waveguide directly onto photovoltaic cells. A 45°coupler is placed at each lens focal point to couple light into the waveguides.

Design of a lens-to-channel waveguide system as a solar concentrator structure.

We present a lens-to-channel waveguide solar concentrator, where the lens array and the channel waveguide act as the primary and the secondary concentrator. Sunlight collected by the lens array is coupled into channel waveguides and exits from one end of the tapered waveguide directly onto photovoltaic cells. A 45° coupler is placed at each lens focal point to couple light into the waveguides.

Highly sensitive compact refractive index sensor based on phase-shifted sidewall Bragg gratings in slot waveguide.

The geometrical and physical parameters of phase-shifted sidewall Bragg gratings in a silicon slot waveguide are optimized to possess performance characteristics desirable for integrated optical sensors. By tailoring the spectral response of such phase-shifted sidewall gratings, highly sensitive compact refractive index sensors detecting the resonance wavelength shift or the variation of light intensity are designed with the transfer matrix method. Both refractive index sensors have a minimum detection limit on the order of 10(-6), and a linear response and a compact structure dimension as small as 11.

Linear photonic frequency discriminator on As₂S₃-ring-on-Ti:LiNbO₃ hybrid platform.

We report a photonic frequency discriminator built on the vertically integrated As₂S₃-ring-on-Ti:LiNbO₃ hybrid platform. The discriminator consists of a Mach Zehnder interferometer (MZI) formed by the optical path length difference (OPD) between polarization modes of Ti-diffused waveguide on LiNbO₃ substrate and a vertically integrated As₂S₃ race-track ring resonator on top of the substrate. The figures of merit of the device, enhancement of the signal-to-3rd order intermodulation distortion (IMD3) power ratio and corresponding 3rd order intercept point (IP3) over a traditional MZI, are demonstrated through device characterization.

Fully reconfigurable compact RF photonic filters using high-Q silicon microdisk resonators.

We present a fully reconfigurable fourth-order RF photonic filter on SOI platform with a tunable 3-dB bandwidth of 0.9-5 GHz, more than 38 dB optical out-of-band rejection, FSR up to 650 GHz, and compact size (total area 0.25 mm(2)).

Low-loss chalcogenide waveguides on lithium niobate for the mid-infrared.

We demonstrate low-loss chalcogenide (As(2)S(3)) waveguides on a LiNbO(3) substrate for the mid-IR wavelength (4.8 μm). Designed for single-mode propagation, they are fabricated through photolithography and dry-etching technology and characterized on a mid-IR measurement setup with a quantum cascade laser.

Mid-infrared characterization of solution-processed As2S3 chalcogenide glass waveguides.

An etch-free and cost-effective deposition and patterning method to fabricate mid-infrared chalcogenide glass waveguides for chemical sensing applications is introduced. As(2)S(3) raised strip optical waveguides are produced by casting a liquid solution of As(2)S(3) glass in capillary channel molds formed by soft lithography. Mid-IR transmission is characterized by coupling the output of a quantum cascade (QC) laser (lambda = 4.