A presente invenção refere-se a um compacto conversor fotônico para sinais de radiofrequência (RF) que apresenta um menor número de componentes que o estado da técnica. O campo da invenção é da área da Eletrônica, circuitos osciladores, circuitos de radiofrequência e optoeletrônica. O conversor é composto por um oscilador optoeletrônico (OEO) (1), que é o oscilador local (LO) da operação de conversão de frequência e um circuito de injeção do sinal de RF (9). O OEO (1) utiliza um único modulador eletro-óptico Mach-Zehnder (MZ) (3) e um único fotodetector (4) possibilitando a conversão simultânea de frequência para valores acima e abaixo (down/up converter) do sinal de radiofrequência da entrada do conversor. A conversão de frequência é baseada na intermodulação que ocorre dentro do modulador MZ.

Système laser caractérisé en ce qu'il comprend une source laser présentant une plage de verrouillage autour d'une fréquence libre f₀, un résonateur optique, placé en sortie de la source laser, présentant un mode de résonance compris dans la plage de verrouillage de la source laser, et un amplificateur optique générant de l'émission spontanée à la fréquence dudit mode de résonance compris dans la plage de verrouillage de la source laser, le résonateur étant agencé de manière à ce qu'il soit couplé avec la source laser et l'amplificateur.

La présente invention concerne un oscillateur (10) radiofréquence comprenant un résonateur (18) optique étant un guide d'ondes en anneau permettant la propagation d'une première onde dans un premier sens et d'une deuxième onde dans un deuxième sens, le deuxième sens étant opposé au premier sens, et le résonateur (18) comportant un milieu optique actif générant une première raie optique à partir de la première onde et une deuxième raie à partir de la deuxième onde, le résonateur (18) étant en contact avec une partie réalisée en un matériau à effet magnéto-optique, un applicateur (20) de champ magnétique externe d'intensité réglable sur le résonateur (18) générant un décalage en fréquence entre la première onde et la deuxième onde, et un circuit de traitement convertissant le battement entre les deux raies optiques en un signal radiofréquence.

An optoelectronic oscillator (OEO) is disclosed comprising an electronically tunable filter for transposing narrow pass band characteristics of a surface acoustic wave (SAW) filter to a microwave frequency to provide mode selection in the OEO. An OEO is disclosed comprising a set of optical domain components, a downconverter in communication with an output of the optical domain components, and a set of radio frequency (RF) domain components in communication with an output of the downconverter. The set of RF domain components comprises a tunable filter operating at a filter center frequency and having an output coupled to the set of optical domain components for communicating a mode selection result. The tunable filter including a tuner; and a sub-filter. The sub-filter operating at a fixed center frequency to provide mode selection and adjacent mode suppression with respect to the tunable filter center frequency. The sub-filter center frequency being lower than the tunable filter center frequency, and a ratio of the tunable filter center frequency to a bandwidth of the sub-filter being at least 1000:1.

Low phase noise radio frequency (RF) sources generated by voltage controlled oscillators (VCOs) are described. Optical modulators driven by a VCO may be used to generate optical side-bands to cw lasers. The spectral extent of said side-bands can be increased via frequency broadening in highly nonlinear waveguides. Free running mode locked low phase noise comb oscillators can be used as reference oscillators to generate beat signals between those side-bands and individual comb modes at distal spectral regions, thereby creating an error signal used to reduce the phase noise of VCOs and the generation of low phase noise RF signals. VCO phase noise may be reduced by using free-running modelocked comb lasers phase locked to external frequency references, by omitting a reference comb and using a nonlinear interferometer for generating an error signal, or by locking a slave comb to the modulation frequency of an intra-cavity modulator driven by the VCO.

Optoelectronic oscillator systems and an optoelectronic oscillator noise reduction method. One example of an optoelectronic oscillator system includes an optical source positioned at a first end of a fiber-optic path, the optical source being configured to transmit an optical signal along the fiber-optic path, an optical modulator positioned to receive and modulate the optical signal based on at least a reference signal, a retro-reflector positioned at a second end of the fiber-optic path, the retro-reflector being configured to receive and retro- reflect the optical signal, the retro-reflected optical signal having at least a frequency range of inherent fiber noise canceled, and an optical circulator positioned along the fiber-optic path between the optical modulator and the retro-reflector, the optical circulator being configured to direct the optical signal to the retro-reflector and direct the retro-reflected optical signal along a feedback path to a first photodetector to generate the reference signal.

A device for generating an electrical signal with a wide band arbitrary waveform comprising a modulator block comprising an input port, an output port and a plurality of modulators, each modulator being adapted to modulate an optical signal passing from a modulator entrance to a modulator exit by a respective microwave signal; the modulator block further comprising an optical splitter for splitting an optical signal received at the input port into a plurality of signal paths one to each modulator entrance; and an optical combiner for combining the signals received at the modulator exits into a single signal at the output port; at last one of the optical splitter and optical combiner comprising an arrayed waveguide grating; the device further comprising an optical pulse generator connected to the input port of the modulator block via an input signal path; and a photodetector connected to the output port of the modulator block via an output signal path the device further comprising at least one dispersive optical element arranged such that the pulses are dispersed by the at least one optical element either before or after modulation.