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A scheme to perform high-quality (high-Q) W-band (75-110 GHz) microwave photonic filters (MPFs) with tunability and reconfigurability is proposed and experimentally demonstrated. The analysis reveals an inverse proportional relationship between the operating frequency of the MPF and the compensatory ability of the optical spectrum processor (OSP) when mitigating the third-order dispersion (TOD). To extend the operating frequency of the MPF toW-band, we present a TOD precompensation technology implemented by a quadratic phase provider (QPP) device. Providing the OSPwith an additional quadratic phase shift, the QPP can shift and extend the systematic TOD compensation range, thus resolving the operating frequency limit imposed by the conventional OSP-based technique. Combined with an automatic in-line TOD compensation procedure, the systematic TOD can be precisely compensated. With an almost complete cancelation of TOD in the filter, a tunable and reconfigurable single-passband W-band filter with a 3-dB bandwidth of around 15.5 MHz and a record-setting Q-factor of 6459 is obtaine [ABSTRACT FROM AUTHOR]

Third-order dispersion (TOD) is a fundamental parameter to characterize optical fiber. In this paper, we propose a method to precisely measure TOD of an optical fiber by using the amplitude and phase transfer function of a microwave photonic filter (MPF). The fiber under test (FUT) plays an important role in the MPF, of which the transfer function has a quadratic phase distortion due to the TOD of the FUT. Through iteratively modifying the quadratic phase spectral coefficient of the optical signal in the MPF to counteract the TOD effect, the transfer function distortion can be almost compensated. According to the definite relationship between the TOD and the compensation coefficient, we can determine the TOD precisely. In the experiment, the measurement uncertainty of 0.2% is obtained of a dispersion compensating fiber, designed for the compensation of 80 km standard fiber. [ABSTRACT FROM PUBLISHER]

A tunable ultraflat optical frequency comb generator based on the optoelectronic oscillator (OEO) using a dual-parallel Mach--Zehnder modulator (DPMZM) is proposed and experimentally demonstrated. By incorporating a tunable DPMZM-OEO, five comb lines were generated with frequency spacing from 5 to 12 GHz under a wide central wavelength tuning from 1530 to 1560 nm, and a comb flatness of 0.3 dB is obtained. The corresponding signal generated by the DPMZM-OEO is also measured, and the phase noise of the frequency tunable signals is as low as -125 dBc/Hz at 10-kHz frequency offset. [ABSTRACT FROM AUTHOR]

Carrier phase and amplitude manipulation is an important signal processing method in microwave photonics. The authors proposed a series of work by realizing such manipulation with a single drive dual-parallel Mach-Zehnder modulator (DPMZM). By controlling the phase of the optical carrier, dispersion compensation can be achieved, while the amplitude tuning of the optical carrier can decrease the nonlinear distortions and improve the linearity. This manipulation method can also help establishing a millimeter-wave photonic up-converter, a frequency doubled opto-electronic oscillator, or a low-interference dual-direction radio-over-fiber (RoF) links. [ABSTRACT FROM AUTHOR]

The main-to-sidelobe suppression ratio (MSSR) is significant to filters. The tap weight errors worsen the MSSR of the finite impulse response (FIR) microwave photonic filters (MPFs). The MSSR can be improved by shaping the multicarrier optical source spectra with high precision. By compensating the errors with an iteration method, the sidelobes of the amplitude response can be optimized to increase the MSSR. Such a method is simple, effective, and compatible with all FIR MPF approaches. In the experiment, optical spectra of Gaussian profiles were taken as an example, and an MSSR improvement from 50 to 63 dB was demonstrated. [ABSTRACT FROM AUTHOR]