Continuously tunable incoherent microwave photonic filter using a tunable Mach‒Zehnder interferometer as the slicing filter

A tunable single-passband microwave photonic filter with positive and negative taps using a fiber Mach–Zehnder interferometer and phase modulation

“…The continuous sampling tap weight distribution of the cosine-like transmission spectrum of the MZI results in the desirable single-passband frequency response. However, this filter is based on incoherent operation, in which negative taps are difficult to obtain, thus limiting the filters' performance, e.g., there is always a dc resonance at the baseband [4][5][6]. It has been reported that phase modulation to intensity modulation (PM-IM) conversion in a dispersive medium can generate a notch at the dc frequency, thus it can be used to eliminate the baseband resonance [7].…”

“…A microwave photonic filter with non-uniformly spaced taps has been reported to increase the free spectral range (FSR) [4]; however, basically, it still has periodical characteristics. Microwave photonic filter with a single passband was proposed and analyzed by using a fiber Mach-Zehnder interferometer (FMZI) as the slicing filter [5,6]. The continuous sampling tap weight distribution of the cosine-like transmission spectrum of the MZI results in the desirable single-passband frequency response.…”

Optical length-change measurement based on an incoherent single-bandpass microwave photonic filter with high resolution

“…The key device in an MPF is the optical delay-line module that can be implemented using optical couplers [8,9], fiber Bragg gratings (FBGs) [10][11][12], Mach-Zehnder lattices [13], arrayed waveguide [14,15], or a length of dispersive fiber [16,17]. Many efforts have been made to achieve tunable MPFs [18][19][20][21][22]. Their applications focus mainly on high-speed signal selecting.…”