Verfahren und System zur Erzeugung von Millimeter- oder Terahertzwellen durch Überlagerung zweier optischer Wellen unterschiedlicher Frequenz, wobei ein Frequenzkamm erzeugt und in Ausbreitungsrichtung in ein optisch nichtlineares Medium, insbesondere eine Singlemode Faser (4), eingekoppelt wird, wobei zwei Pumpwellen erzeugt und entgegen der Ausbreitungsrichtung in das optisch nichtlineare Medium eingekoppelt werden, wobei die Wellenlängen der Pumpwellen derart eingestellt werden, dass sie zwei Frequenzen aus dem Frequenzkamm vermittels stimulierter Brillouin Streuung verstärken, wobei die beiden verstärkten Frequenzen in Ausbreitungsrichtung aus dem Medium ausgekoppelt und in einem optischen Sensor, insbesondere einer Photodiode (12), heterodyn überlagert werden, wobei die Überlagerung einem Ausgangssignal des Sensors (12) eine Differenzfrequenz aufprägt, die ausgekoppelt wird, wobei der Frequenzkamm mittels einer einzigen modengekoppelten Laserquelle, insbesondere mittels eines Kurzpuls-Lasers (1), erzeugt wird, und wobei die Pumpwellen auf die beiden zu verstärkenden Frequenzen stabilisiert und nicht zu verstärkende Frequenzen des Frequenzkamms unterdrückt werden.

This invention discloses a photonic system to beamform the electric field yield by a phased array antenna. The system function relies on a photonic tunable delay line, which consists on an optical Mach-Zehnder interferometer with a predefined time delay difference between arms. The time delay is tuned by adjusting the coupling ratio between the power applied to each one of the interferometer's delay lines. Three embodiments are proposed, wherein one of them just uses a single delay line and a single monchromatic light source, independently of the quantity of the array elementary antennas.

In accordance with various aspects of the disclosure, a method and apparatus is disclosed for increasing waveform bandwidth of a radio frequency waveform during optical double sideband suppressed carrier modulation. An optical modulator is configured to operate in double sideband, suppressed carrier modulation (DSB-SC) mode producing multiple optical sidebands and optical sideband harmonics. Proper selection of the appropriate optical harmonic via optical filter enables the synthesis of ultra-wideband single-sideband, suppressed carrier (SSB-SC) optical waveforms while simultaneously simplifying the radio frequency (RF) circuitry that generates the radio frequency waveform.

Devices and techniques for frequency conversion of radio frequency (RF) or microwave signals based on photonic processing.

It is provided a practical radio oscillating system for a radar system to alleviate the necessity of a reception filter of severe specification of pass band and an oscillating system and an amplifier of high performance and high reliability. The radio oscillating system has an optical modulator 2 for oscillation; a modulating means 6 for modulating a carrier wave "P" passing through the optical modulator 2 so as to superimpose sideband waves "Q" and "R" onto the carrier wave; an optical receiver 7 for oscillation to receive outgoing light "B" from the optical modulator 2 and to convert the outgoing light into an electrical signal; and a radiating means 8 for radiating radio signal "C" based on the electrical signal.

A versatile photonic radio frequency (RF) oscillator employs a single optical feedback loop, or multiple feedback loops of different delay times and including at least one optical feedback loop, to generate RF signals with ultra-low phase noise, narrow spectral linewidth, and a continuous wide tuning range of high resolution. Specifically, an electro-optical modulator and a long optical fiber loop are implemented in one dual-loop system. In addition, a light beam from a light source can be directly modulated by using a single optical feedback signal, or a plurality of feedback signals from multiple feedback loops, to alter the electrical control signal to the light source. Furthermore, the disclosed system supports both electrical and optical RF outputs. External optical injection and electrical injection can be implemented.

Described herein is a multi-input receiver (MIR) arrangement that comprises a photodiode array (210) and coherent summing means (240). The photodiode array (210) receives optical signals having RF information impressed thereon and includes a plurality of photosensitive elements (220) and a plurality of electrical contacts (230). The coherent summing means (240) sums the RF information to provide an RF output signal in a way that the signal from each photosensitive element (220) adds vectorially in phase. The coherent summing means (240) comprises a coplanar transmission line (240) formed on a substrate (250), the impedance of the coplanar transmission line (240) being matched to the photodiode array (210) by adjusting parameters of the coplanar transmission line (240).

A channelizer for optically channelizing RF signals modulated onto an optical carrier by optically separating the RF signals and mapping the RF signals by way of an optically dispersive element 22, such as a diffraction grating. In an alternate embodiment of the invention, two stages of optical filters elements are provided in series to perform sequential channelization. Bragg reflection gratings 31,33 are used for coarse filtering into predetermined bands while Fabry-Perot filters tuned to specific sub-bands of the Bragg reflection gratings 31, 33 are used for channelization. In alternate embodiments of the invention, a silica planar waveguide and a optical splitting device, such as a Talbot splitter, are used.