USA As Represented by Secretary of the Navy

Ross Schermer

Carl A Villarruel

Frank Bucholtz

Janet W Lou

Jason D McKinney

Colin McLaughlin

Systems and methods are provided for non-uniform optical sampling with wider optical bandwidth and lower timing jitter than conventional systems, which can make non-uniform optical sampling more feasible. Embodiments of the present disclosure further provide systems and methods for determining all input signal frequencies, including those left ambiguous by prior methods.

Delay-modulation-based non-uniform optical sampling and frequency disambiguation

A system testing the speed of a microwave photonic system, having a Mach Zehnder interferometer that includes a first arm with a photonic system to be tested and an amplifier arranged to amplify the output of the photonic system, and a second arm with an attenuator configured to match the output power of the amplifier, with at least one filter arranged at the output of the Mach Zehnder interferometer, the filter having a pass band that includes the center frequency of a continuous wave microwave signal applied to the Mach Zehnder interferometer arms. A continuous wave microwave signal is applied to the input of the Mach Zehnder interferometer, a signal is applied to only the second arm with the photonic link, and the output of the bandpass filter is measured with an oscilloscope and a microwave power detector.

System and method for testing the speed of a microwave photonics system

A true time delay system for optical signals includes a hollow core optical waveguide, a droplet of reflective liquid metal disposed in the hollow core, and an actuator coupled to a first end of the waveguide to move the droplet longitudinally within the hollow core. In one example, the waveguide is a hollow core photonic bandgap fiber. In one example, the actuator is a pressure actuator that introduces or removes gas into the core. Light enters the optical fiber, is transmitted through the fiber toward the reflective surface of the droplet, and is reflected back through the fiber and exits at the same end of the photonic bandgap optical fiber that it entered. The fiber optic device can provide a continuously-variable optical path length of over 3.6 meters (corresponding to a continuously-variable true-time delay of over 12 ns, or 120 periods at a 10 GHz modulation frequency), with negligible wavelength dependence across the C and L bands.

Reconfigurable liquid metal fiber optic mirror

A true time delay system and method for an optical carrier signal modulated with a microwave signal. The system includes a beam deflector, with the optical signal being imaged onto the beam deflector, a stationary reflective diffractive grating arranged in a Littrow configuration, a focusing element arranged between the beam deflector and the stationary reflective diffractive grating. In operation, the beam deflector steers the optical beam across the clear aperture of the focusing element and the focusing element transmits the steered beam to the reflective diffractive grating. A change in optical path length experienced by the optical beam as the beam is scanned across the grating surface results in a relative phase delay in the optical beam. The beam deflector can be a rotating mirror, an acousto-optic beam deflector, or an electro-optic beam deflector. The focusing element can be a lens or a curved mirror.

Microwave photonic true-time-delay

An apparatus for creating sheathed flow includes an inlet section comprising an array of tubes including at least one sheath inlet port and a sample inlet port, a flow focusing section downstream from the inlet section, an optical access section downstream from the flow focusing region and comprising opposing flat surfaces, and an outlet section downstream from the optical access section, wherein the apparatus is operable to create a sheathed flow around a fluid introduced into the sample inlet port and to maintain the sheathed flow through the optical access section. Applications of the apparatus and method include bead/particle counting, flow cytometry, waveguiding, and fluid control.

Tubular array for fluidic focusing with integrated optical access region

The application of an optical beam redirects sheathed micro-fluidic flow without direct interaction with the sample. The hydrodynamic properties of the sheath are locally modified due to optical absorption and heating, resulting in a spatial shift of the sample flow. The technique can result in up to 100 &#x3bc;m shift at peak flow velocities of 19 mm/sec.

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Springfield, VA, United States of America

Ross Schermer