Other

US Government As Represented by the Secretary of the Army

USA As Represented by Secretary of the Navy

The University of Alabama

Time Domain Corporation

Mark J Bloemer

Michael Scalora

Michael D Tocci

Jonathan P Dowling

Charles M Bowden

Giuseppe D'Aguanno

Marco Centini

Concita Sibilia

William C Pittman

Richard L Fork

Nadia Mattiucci

Krishna Myneni

Salvatore Baglio

Evgenl Y Poliakov

Rachel J Flynn

Senter B Reinhardt, Jr

We have shown that a single layer of a 3D Zero Index Material (ZIM) has omnidirectional reflection properties. In the range between the electric plasma frequency and the magnetic plasma frequency, ZIM reflect radiation for all angles of incidence and polarization with reflectivities of &#x2dc;99%. In addition, with increasing angles of incidence, the reflecting band does not shift in frequency but actually widens. The operational bandwidth can be 100% or greater by increasing the separation between the electric and magnetic plasma frequencies. We have also shown that in the spectral region that allows the omnidirectional gap, ZIM can be used as the cladding of hollow waveguides with better performance than traditional hollow waveguides.

Zero index material omnireflectors and waveguides

A waveguide has upper and lower cladding regions. A core of the waveguide made of a non-linear optical polymer is positioned between the upper and lower cladding regions. A first electrode is connected to the upper cladding region and a second electrode is connected to the lower cladding region. The upper cladding region and the lower cladding region are made of photonic band gap materials and have multiple periods of cladding layers with each period having a first layer having a linear refractive index of nand each period having a second layer having a linear refractive index of n. The waveguide allows for minimal distances to exist between the electrodes while allowing for virtual lossless cm-long transmission of propagating light. By applying a voltage to the electrodes, the propagated light can be modulated.

Photonic crystal-based optical waveguide modulator

An LCD device for displaying an image includes pixel control electrodes constructed as a transparent metal stack having a photonic band gap (PBG) structure that transmits a visible range of wavelengths and suppresses a non-visible range of wavelengths. A liquid crystal layer between the pixel control electrodes controls the transmission of light in response to a voltage applied across the pixel control electrodes. A light emitting structure (LES), such as a light emitting diode (LED) or light emitting polymer (LEP) device includes a cathode electrode, a substrate, an active layer for emitting visible light, and a transparent anode electrode having a PBG structure.

Liquid crystal display device and light emitting structure with photonic band gap transparent electrode structures

A photonic band gap (PBG) device is provided for frequency up and/or down-converting first and second photonic signals incident on the device to produce a down-converted output photonic signal. When the first and second incident photonic signals have respective first and second frequencies &ohgr; and &ohgr; , the down-converted photonic signal has a third frequency &ohgr; &equals;&ohgr; &minus;&ohgr; . When the first incident field has a frequency &ohgr; , the first up-converted photonic signal has a second frequency &ohgr; . The second up-converted photonic signal has a third frequency &ohgr; &equals;&ohgr; &plus;&ohgr; . Thus, the PBG device can be used to generate coherent near- and mid-IR signals by frequency down-converting photonic signals from readily available photonic signal sources, or red, blue, and ultraviolet signals by up-converting the same readily available photonic signal sources.

Photonic signal frequency up and down-conversion using a photonic band gap structure

In the monolithically integrated photonic circuit, light travels through multiple quantum well channel waveguides and is coupled into and out of the devices that reside in common on a single semiconductor substrate. Each device, which is co-planar with any other device on the substrate, is comprised of a quantum well channel waveguide of a pre-determined length and an electrical contact pad mounted on the waveguide that facilitates the application of electric field to the device. The function of any particular device as an optical source, an optical modulator or a photo-detector is determined by the bias mode of electric field applied to that particular device. The circuit is comprised of multiple rows of such devices. Each of these rows contains at least three devices which function as an optical source, an optical modulator and a photo-detector, respectively, and are separated from each other by electrical isolation gaps.

Monolithically integrated photonic circuit

A device is provided for generating a photonic signal having a phase different from an input photonic signal that is incident on the device. The input photonic signal has an signal frequency, signal bandwidth, and a signal intensity. The device comprises a plurality of material layers. The material layers are arranged such that the device exhibits a photonic band gap structure. The photonic band gap structure exhibits a transmission band edge that corresponds to the input photonic signal frequency. A second photonic signal is generated at a second photonic frequency preferably close to a second band edge. The interaction of the input photonic signal with the second photonic signal generates a phase shift of order &pgr; for relatively small input intensities.

Efficient non-linear phase shifting using a photonic band gap structure

Non-linear reflectivity and non-linear transmissivity of a first photonic signal incident on a photonic band gap (PBG) structure are controlled by applying a second photonic signal to the PBG structure while the first photonic signal is incident on the PBG structure. The first and second photonic signals have respective frequencies near a low frequency, first order band gap edge and a high frequency, second order band gap edge resonance peak of the PBG structure. The first photonic signal undergoes enhanced non-linear gain near the band gap edges when a predetermined phase difference is imposed between the first and second photonic signals, resulting in dramatic reflectivity and transmissivity changes for a band gap structure of only a few microns in length.

Photonic signal reflectivity and transmissivity control using a photonic band gap structure

The photonic band gap (PBG) dual-spectrum sensor utilizes the frequency-selective properties of a photonic band gap device constructed in accordance with this invention to separate incident electromagnetic wave into two frequency bands. The parameters of the PBG device are chosen so that one frequency band is transmitted through the device with low attenuation while the second band is reflected with low attenuation from the front face of the device. This separation of the two frequency bands allows separate detection processes to be performed to recover the information content of the two signals before the information is fused in subsequent signal processing operation. Such a PBG device would be useful in missile seekers that seek to distinguish a target object from its background.

Photonic band gap dual-spectrum sensor

A photonic band gap structure device and method for delaying photonic signals of a predetermined frequency and a predetermined bandwidth by a predetermined delay is provided. A Fabry-Perot delay line device has several regions of periodically alternating refractive material layers which exhibit a series of photonic band gaps and a periodicity defect region, interposed between the regions of periodically alternating refractive material layers. The Fabry-Perot delay line device imparts a predetermined delay to photonic signals that pass therethrough. The introduction of the periodicity defect region into this photonic band gap structure creates a sharp transmission resonance within the corresponding photonic band gap of the structure and causes at least an order of magnitude improvement in photonic signal delay for a band-edge delay line device of similar size. Variable photonic delays to multiple photonic signals are also generated by this Fabry-Perot delay line device. In addition, a photonic signal delay device based on an optical fiber grating structure is provided.

Photonic band gap device and method using a periodicity defect region to increase photonic signal delay

A device and method of optics propagation and signal control integrated with micro-electro-mechanical-switches (MEMS). This device modifies optical transmission properties of a transparent multilayer metal stack by mechanically varying the thickness of an air gap between layers in the stack This is accomplished by utilizing MEMS coupled with the stack to change the optical path in a given layer of the transparent multilayer metal stack. This can be accomplished by developing a hybrid combination of transparent multilayer stacks and MEMS, wherein an air gap is used as one of the dielectric layers. The air gap thickness can be controlled by the MEMS device thereby enabling dramatic control of the optical path.

Apparatus and method for controlling optics propagation based on a transparent metal stack

A novel SH generator based on a photonic band gap (PBG), mixed half-quarter-wave, periodic structure is described. Both energy output and conversion efficiencies are nearly three orders of magnitude greater than for bulk, phase-matched devices of comparable lengths. Similar results for a GaAs/AlAs semiconductor periodic structure are also found. These results have immediate applications in frequency up- and down-conversion lasers, higher and lower harmonic generation, and Raman-type lasers, where either Stokes or anti-Stokes resonances can be enhanced or suppressed near the band edge. In general, the underlying mechanism requires the fields to be strongly confined, allowing for longer interaction times, increased effective gain lengths, and enhanced conversion efficiencies, although strong pump confinement alone can also result in significantly enhanced SH generation.

Photonic signal frequency conversion using a photonic band gap structure

Photonic band gap device and method using a periodicity defect region to

A photonic signal is applied to a photonic bandgap structure having a photonic band edge transmission resonance at the frequency of the photonic signal and having a photonic band edge transmission resonance bandwidth which is at least as wide as the bandwidth of the photonic signal. When a photonic band edge transmission resonance is matched to the photonic signal which is being transmitted, a controllable delay is imparted to the photonic signal without significantly altering the photonic signal itself.

Photonic bandgap apparatus and method for delaying photonic signals

An optical switch in a one-dimensional multilayer dielectric stack having a photonic band gap, composed of at least two groups of layers of dielectric material whose operating wavelength is near the edge of said photonic band gap. At least one layer of each of the groups is composed of a nonlinear c.sub.3 dielectric material, which creates an intensity-dependent shift in the location of the band gap and produces a dynamical change in the transmissive and reflective properties of the multilayer dielectric stack in response to changes in the intensity of light or the transmittance of electromagnetic radiation passing through the multilayer dielectric stack. The width of the photonic band gap is determined by the differences between the refractive indices of the nonlinear dielectric material and that of the other layers of dielectric material in the multilayer dielectric stack.

Optical switch that utilizes one-dimensional, nonlinear, multilayer

A new optical diode is disclosed that permits unidirectional transmission of light, the direction of transmission depending on the direction of incidence. The diode comprises a stack of alternating layers of a low-index material and a high-index material. The layers are arranged within the stack such that there is spatial anisotropy of optical pathlengths in the stack and at least the low-index layers or the high-index layers have an optical nonlinearity, either inherently or by doping. At sufficiently high incident intensifies and appropriate wavelengths, such a diode exhibits partial transmission of input light incident from one direction while reflecting almost totally input light incident from the opposite direction.

Growing community of inventors

Athens, AL, United States of America

Mark J Bloemer