A novel squint-free, continuously tunable beamformer mechanism for a phased array antenna system is proposed. It consists of filter-based optical single-sideband suppressed-carrier modulation, a fully integrated optical beam forming network using cascades of optical ring resonators as tunable delay elements, and balanced coherent optical detection. The proposed system brings advantages in optic...

We propose and experimentally demonstrate a continuous wave (CW) tunable-wavelength fiber laser using self-seeding Fabry-Perot laser diode (FP-LD) without optical amplifier inside gain cavity. By employing a tunable bandpass filter (TBF) and a fiber reflected mirror (FRM) within a gain cavity, the fiber laser can lase a single-longitudinal wavelength due to the self-seeding operation. The propo...

Wideband and frequency-tunable microwave signal generation using an optoelectronic oscillator incorporating a Fabry-Perot laser diode (FP-LD) with external optical injection is proposed and demonstrated. Through external injection, the FP-LD functions as a tunable high-Q photonic microwave filter, and the frequency tuning is realized by either tuning the wavelength of the externally injected op...

We present a continuously tunable nonrecursive radio-frequency (RF) photonic filter. The filter provides fine tuning through the use of a novel RF phase shifter and coarse tuning using an all optical variable time delay. This architecture permits wide-band continuous tuning of the filter null frequency and is useful in applications such as moving target indication (MTI) in an airborne radar.

Tunable filters for wavelength-division multiplexing transmission system are essential. Fiber Bragg grating (FBG) is one of the best candidates for this application. The wavelength shift of FBGs can be tuned by applying different temperature, hydrostatically pressure and strains (in traction or/and compression). A comprehensive study of using these three parameters as being tunable filters was ...

We propose and demonstrate a tunable photonic radio frequency notch filter. The filter has a single delay line architecture and incorporates a new wavelength-selective true-time-delay. The time delay in the feed-forward ioop can be varied by simply changing the optical wavelength resulting in a shift of the null of the filter response. Application in radar systems is discussed.

We demonstrate an automatic tunable transversal notch filter based on uniform fiber Bragg gratings and a broadband optical source. High tunability can be performed by stretching the fiber with the gratings written in series. Also, high sidelobe supression can be achieved by introducing tunable attenuators in a parallel configuration of the gratings.

An integrated photonic architecture is introduced and used to realize an optical filter with direct form I realization. The architecture offers gain from semiconductor optical amplifiers, and this gain results in an active optical filter whose filter response depends on the individual gains. The presence of gain provides advantages in filter performance, and tunable and adaptive functionality. ...

We experimentally characterize the performance of a continuously tunable all-optical complex-coefficient finite-impulse-response (FIR) filter that exploits nonlinear signal processing (multiplexing and multicasting) and conversion-dispersion-based optical delays. Various length (three and four) optical FIR filters with different tap amplitudes (from 0 to -9 dB), tap phases (from 0 to 2π), and t...

We demonstrate an all-fiber tunable polarization filter with high coupling efficiency based on acousto-optic coupling between two optical polarization modes of the LP(01) mode propagating in a highly birefringent single mode optical fiber. An over-coupling between the two polarization modes is realized over the wavelength range from 1530 nm to 1610 nm using traveling torsional acoustic wave. Th...