Alexander Miles

Design and Preliminary Implementation of an N

We have demonstrated a diffraction-based nonblocking, scalable N × N optical switch employing a digital micromirror display (DMD) with 12 μs switching speed, performing 100 times faster than the currently available technology. The distributed nature of diffraction makes this switch more robust than one-to-one reflective systems where a single mirror failure incapacitates an entire connection. We thereby address a key bottleneck in data centers and optical aggregation networks by decreasing circuit-switching speed and allowing for facile port count scalability.

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Magneto-optical (MO) composites with excellent Faraday rotation (FR) response were fabricated using iron platinum (FePt) nanoparticles (NPs) and polystyrene-block-poly (2-vinyl pyridine) (PS-b-P2VP) block copolymers (BCPs). Gallic acid functionalized FePt NPs with average core diameters (dcore) of 1.9, 4.9, 5.7 and 9.3 nm have been selectively incorporated into a P2VP domain through hydrogen bonding interactions. The use of copolymer templates to selectively arrange the magnetic NPs guaranteed high MO performance with little trade-off in terms of scattering loss, providing a simple strategy to prepare functional materials for MO applications. As a result, Verdet constants of a 10 wt % loaded 4.9 nm FePt NP composite reached absolute magnitudes as high as ~-6 × 104 °/T-m at 845 nm, as determined by FR measurements at room temperature. At the same time, the MO figure-of-merit was as large as −25 °/T in these composites, indicating both excellent MO performance and transparency. The dependence of the nanocomposite FR properties on particle diameter, loading (from 0.1 wt % to 10 wt %) and composite nanostructure were systematically investigated at four infrared wavelengths (845, 980, 1310 and 1550 nm).

N Diffractive All-Optical Fiber Optic Switch

We have developed an approach for designing a dichroic coating to optimize performance of current-matched multijunction photovoltaic cells while diverting unused light. By matching the spectral responses of the photovoltaic cells and current matching them, substantial improvement to system efficiencies is shown to be possible. A design for use in a concentrating hybrid solar collector was produced by this approach, and is presented. Materials selection, design methodology, and tilt behavior on a curved substrate are discussed.

Improving Faraday rotation performance with block copolymer and FePt nanoparticle magneto-optical composite

Hybrid thermal-PV solar trough collectors combine concentrated photovoltaics and concentrated solar power technology. In this work, we analyze the optical and mechanical tolerances that affect the solar energy collection using non-sequential ray tracing techniques. The study is complemented with a half scale prototype characterization. We aim to establish a basis for tolerances required for fabrication and manufacturing of such systems.

Designing spectrum-splitting dichroic filters to optimize current-matched photovoltaics

Complex Faraday effect and magnetic permeability measurements on iron-platinum (FePt) nanoparticles embedded in a polystyrene-poly(2-vinyl)pyridine (PS-P2VP) copolymer matrix are reported. Possible applications include high performance biomagnetic field sensors and optical isolators.

Tolerance Analysis and Characterization of Hybrid Thermal-PV Solar Trough Prototype

Presented here is a 32 × 32 optical switch for telecommunications applications capable of reconfiguring at speeds of up to 12 microseconds. The free space switching mechanism in this interconnect is a digital micromirror device (DMD) consisting of a 2D array of 10.8μm mirrors optimized for implementation at 1.55μm. Hinged along one axis, each micromirror is capable of accessing one of two positions in binary fashion. In general reflection based applications this corresponds to the ability to manifest only two display states with each mirror, but by employing this binary state system to display a set of binary amplitude holograms, we are able to access hundreds of distinct locations in space. We previously demonstrated a 7 × 7 switch employing this technology, providing a proof of concept device validating our initial design principles but exhibiting high insertion and wavelength dependent losses. The current system employs 1920 × 1080 DMD, allowing us to increase the number of accessible ports to 32 × 32. Adjustments in imaging, coupling component design and wavelength control were also made in order to improve the overall loss of the switch. This optical switch performs in a bit-rate and protocol independent manner, enabling its use across various network fabrics and data rates. Additionally, by employing a diffractive switching mechanism, we are able to implement a variety of ancillary features such as dynamic beam pick-off for monitoring purposes, beam division for multicasting applications and in situ attenuation control.

Verdet constant and magnetic permeability in microstructured FePt nanoparticles in PS-P2VP copolymer composite films

We present here the use the DMD as a diffraction-based optical switch, where Fourier diffraction patterns are used to steer the incoming beams to any output configuration. We have implemented a single-mode fiber coupled N X N switch and demonstrated its ability to operate over the entire telecommunication C-band centered at 1550 nm. The all-optical switch was built primarily with off-the-shelf components and a Texas Instruments DLP7000™with an array of 1024 X 768 micromirrors. This DMD is capable of switching 100 times faster than currently available technology (3D MOEMS). The switch is robust to typical failure modes, protocol and bit-rate agnostic, and permits full reconfigurable optical add drop multiplexing (ROADM). The switch demonstrator was inserted into a networking testbed for the majority of the measurements. The testbed assembled under the Center for Integrated Access Networks (ClAN), a National Science Foundation (NSF) Engineering Research Center (ERC), provided an environment in which to simulate and test the data routing functionality of the switch. A Fujitsu Flashwave 9500 PS was used to provide the data signal, which was sent through the switch and received by a second Flashwave node. We successfully transmitted an HD video stream through a switched channel without any measurable data loss.

Microsecond regime optical cross connect: 32 port to 32 port scalable device

We developed a scalable optical switch with a 12 μs reconfiguration time that is polarization, data rate, and protocol agnostic. The system can be configured as a cross connect for hybrid data center architecture, or as a wavelength selective switch with flexible channel bandwidth for ROADM and software defined network applications.