USA As Represented by Secretary of the Navy

Marc Currie

Virginia D Wheeler

Francis J Kub

Igor Vurgaftman

Jon-Paul Maria

Joshua D Caldwell

Janet W Lou

David Kurt Gaskill

Thomas S Clark

Thomas F Carruthers

Guy Beadie

Anindya Nath

A method for locally annealing and crystallizing a thin film by directing ultrashort optical pulses from an ultrafast laser into the film. The ultrashort pulses can selectively produce an annealed pattern and/or activate dopants on the surface or within the film.

Ultrafast laser annealing of thin films

A tunable spectral filter comprising a phase change material is incorporated into a multilayered dielectric structure. The dielectric permittivity, and thus the filter properties, of the structure can be modified by producing a change in the phase change material, e.g., causing a metal-insulator transition. By controllably causing such a change in the dielectric permittivity of the phase change material, the spectral transmittance and reflectance of the structure, and thus its filter properties, can be modified to provide a predetermined transmittance or reflectance of electromagnetic radiation incident on the structure. In preferred embodiments, the phase change material layer is a vanadium dioxide (VO) film formed by atomic layer deposition (ALD).

Tunable spectral filters

IR emission devices comprising an array of polaritonic IR emitters arranged on a substrate, where the emitters are coupled to a heater configured to provide heat to one or more of the emitters. When the emitters are heated, they produce an infrared emission that can be polarized and whose spectral emission range, emission wavelength, and/or emission linewidth can be tuned by the polaritonic material used to form the elements of the array and/or by the size and/or shape of the emitters. The IR emission can be modulated by the induction of a strain into a ferroelectric, a change in the crystalline phase of a phase change material and/or by quickly applying and dissipating heat applied to the polaritonic nanostructure. The IR emission can be designed to be hidden in the thermal background so that it can be observed only under the appropriate filtering and/or demodulation conditions.

Frequency- and amplitude-modulated narrow-band infrared emitters

Frequency- and amplitude- modulated narrow-band infrared emitters

An appropriately configured pulsed laser is focused onto a graphene sheet and is used to form a desired pattern in the graphene. When the laser pulse strikes the graphene, it modifies the bonding state of the carbon atoms in the graphene lattice, acting as a 'blade' and causing a separation in the graphene sheet at the site of the laser pulse without causing damage to the surrounding graphene. The width of the separation, or 'cut' in the graphene sheet can be controlled by controlling characteristics of the laser pulse such as beam shape, beam intensity, pulse width, repetition rate, and wavelength to produce a graphene material having desired electrical, optical, thermal, and/or mechanical properties.

Sub-micron laser patterning of graphene and 2D materials

Laser devices are presented in which a graphene saturable absorber and an optical amplifier are disposed in a resonant optical cavity with an optical or electrical pump providing energy to the optical amplifier.

Infrared laser

Ring cavity laser device

A method and system for modifying the detected phase of a signal by driving a photodetector into saturation. This system and method differs from current manual and electrical microwave phase modification by using saturation means for modifying the phase. The system and method may use a plurality of the signal generators for saturating the photodetector.

Method for optical control of microwave phase

This invention pertains to a multipass retroreflector and to a method for its operation. In a preferred embodiment, the retroreflector comprises three reflecting surfaces arranged at an angle to each other in the form of a prism that is triangular in cross-section and 1 to 2 ports through which an optical beam enters and/or exits. The method includes the step of admitting an optical beam into the retroreflector where the optical beam is reflected from the reflecting surfaces and exits parallel to the path of the incoming optical beam. The method also includes the steps of spacing and adjusting angular disposition and dimensions of the reflecting surfaces in order to change path length of the optical beam passing through the retroreflector. This spacing can be continuously scanned causing a large change in optical path length due to a small change in the position of the moving surface.

Multipass optical retroreflector and method of using

A multiple wavelength laser apparatus is taught to select wavelengths for simultaneous generation of short pulses at multiple wavelengths having application in wavelength-division-multiplexed communications systems, photonic microwave systems, and pump-probe applications. The multiple wavelength laser comprises an optical fiber lasing material, a laser pump source connected to said lasing material for outputting coherent light, a splitter for dividing said coherent light into parallel paths of differing wavelengths, parallel band pass filters for selecting multiple wavelengths, and parallel Faraday mirrors for operating the multiple wavelength laser in a single polarization state.

Multiple wavelength pulsed source

This invention discloses a hybrid photonic analog-to-digital converter using superconducting electronics to achieve a high-speeds. This scheme differs from most current designs by combining two systems, photonic and superconducting, to utilize each system for optimal performance. The photonic system performs the optical sampling of the signal with very low aperture and jitter errors. This optically sampled data is then converted to an electronic signal via an optoelectronic switch and quantized in the superconducting system. The high-speed (> GHz) superconducting electronic system transforms the quantized signal into a binary output. This invention allows for analog-to-digital conversion at much higher speeds than available with current electronic analog-to-digital converters.

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Gaithersburg, MD, United States of America

Marc Currie