In this paper, we design the ring resonator filters such as moving average (MA), autoregressive (AR) and autoregressive
moving average (ARMA) filters. These filters are designed as add/drop filter, channel selection and dispersion compensator.
The transfer functions of optical filters are derived using Z-transforms.
In this paper, we present an experimental investigation of all-optical switch using a symmetric Mach-Zehnder
interferometer (MZI) combined with double fiber ring resonators. Here, we replace the ordinary-fiber ring resonator on
one arm of MZI by a 980 nm-laser pumped erbium-doped fiber (EDF) ring resonator to form an EDFA. When adjusting
the EDF pump power up we note increasing in switching power. Experimental results indicate that using MZI with
double EDF ring, switching power is lowered significantly to nanowatt level in comparison with that of MZI with a
single EDF ring of milliwatt level.
We design and simulate a nonsymmetric vernier type of multiple ring resonator (MRR) filters to achieve wider free spectral range (FSR) with different ring radii. The expanded FSR is determined by the least common multiple of the FSRs of the individual ring resonators. The dependence of the transmission characteristics of the MRR on the coupling coefficients of directional couplers is studied. The improvement in suppression of interstitial resonances by using high-order vernier filters is also investigated. A graphical approach with a signal flow graph has been found very useful for quickly deriving the optical transfer functions of filters in the Z domain.
A key device in all optical networks is the optical filter. There are different types of optical filters, for examples, Bragg grating, thin film filter, and arrayed waveguide grating. The use of fiber-optic filters based optical Add/Drop multiplexing (OADM) can process the optical wideband signals in the optical network. In this paper, the designed and simulated filtering characteristics of a serially coupled triple ring optical resonator (STRR) are modeled and investigated. The mathematical relations of the coupling coefficients with the transmission characteristics of the STRR filter are expressed by Z-transform analysis. The transmission spectra of the through port and the drop port of each input of the four-port STRR configuration are simulated. Results are presented on the characteristics of the output as a function of wavelength for various values of the coupling coefficients. With the derived approximate formulas, it is shown that the coupling of the ring fiber system can be changed and thus that the transmission properties of the filter can be controlled and used.