The squeezed photonic crystal fibers have attracted significant attention, which is a kind of photonic crystal fiber with
squeezed lattice or elliptical air holes in cladding. So far there is no a universal concept to describe the squeezed degree.
We introduce the concept of the modified squeezing ratio to describe the squeezed degree of the squeezed photonic
crystal fibers, and then present a corresponding model. Using this model, we investigate the influence of modified
squeezing ratio on the birefringence characteristics of photonic crystal fibers based on the supercell lattice method.
Furthermore, it is reported for the first time to our knowledge that the complex influence of the lattice squeezing and the
elliptical air holes on the birefringence is discussed.
In this paper, we theoretically and experimentally introduce a new reconfigurable optical add/drop multiplexers
(ROADM) module which bases on the narrow-band optical switch (NBOS) technology and achieves the narrow-band
optical switching with a Fabry-Perot cavity. In comparison with the analysis of the current ROADM technologies, the
NBOS-based ROADM module is proven to be cost-effective, low insertion loss, narrow-band, and has a more mature
technology. It would grow to be a cost-effective ROADM solution than any of the others.
We theoretically and experimentally report a single-wavelength module of 1x4 wavelength selective switch (WSS)
module based on the bi-axial MEMS mirror and thin film filter technology. With a cascaded structure of such WSS
module, a novel 1xN WSS can be realized. The insertion loss of 3dB, extinction ratio > 50dB and hitless switching are
A novel polarization dependence loss (PDL) measurement approach using the degree of polarization (DOP) feedback
signal has been introduced in this paper. Both the theoretical analysis and the experimental simulation show that, while
maintaining a very acceptable level of measurement accuracy, this PDL measurement method could effectively reduce
the measurement time. In comparison with the current PDL measurement technologies, the most prominent property of
our method is that it could provide different PDL measurement accuracy and range by changing the value of polarization
mode dispersion (PMD) element in the measurement setup.
The impacts of polarization dependence loss (PDL) on the polarization mode dispersion (PMD) compensation in
return-to-zero (RZ) and non-return-to-zero (NRZ) modulated systems are discussed in this paper. PDL affects the degree
of polarization (DOP) feedback PMD compensation only in the presence of PMD. And in the presence of PMD and PDL,
DOP relates not only to both the PMD and the PDL vectors, but also to the signal's polarization states. In the presence of
PDL, DOP-feedback PMD compensation would be more effective in NRZ system than in RZ system.
In this paper, a modified stacking method to fabricate photonic crystal fibers with squeezed lattice is presented, for the first time to our knowledge. This modified method can realize different structures of photonic crystal fibers with different expected squeezing ratios. The influences of the structural parameters on the squeezing ratio and birefringence are separately discussed in detail. Moreover, the birefringence characteristics of such photonic crystal fibers are simulated by using supercell lattice method.
In this paper, several triangular-lattice highly birefringent PCFs are analyzed on the base of the full vector model. Several properties of them, such as the PCF's modal field, the birefringence and the dispersion, are simulated by the supercell lattice method. Moreover, a comparison is made among them to study the impact of air-holes configuration of PCFs on their propagation properties. The simulation results show that air-holes at different position have different impact on the propagation properties of PCFs.
The impact of polarization dependence loss (PDL) on the degree of polarization (DOP) feedback signal in polarization mode dispersion (PMD) compensation is discussed in this paper. PDL affects DOP only in the presence of PMD. And in the presence of PMD and PDL, DOP relates not only to both the PMD and the PDL vectors, but also to the signal's polarization states. The PDL minimum endangering PMD compensation is determined by the step size of the practical PMD compensating algorithm, and the DGD value in optical fiber systems. DOP could no longer act as the feedback signal in PMD compensation unless PDL in the fiber system has been effectively eliminated before PMD compensation.
In this paper the performance of single channel 40 Gb/s non-return-to-zero (NRZ) signal is studied over standard configured dispersion-management transmission systems (1*80 km/6*80 km). Firstly, the optical and electrical filter bandwidth of receiver is optimized according to the power penalty. Then the nonlinear characteristic is considered. The pre- and post-compensating dispersion is discussed too. We get the conclusion that the optimal optical bandwidth will increase with the increase of SMF input power because of the fiber non-linear effects and the appropriate pre-compensating dispersion will improve the transmission performance and dispersion tolerance.
The theoretical model of DOP degraded by PMD is presented, with which one can analyze and maximize DOP directly from two factors, the magnitude and the direction of the PMD vector. According to this, one method to counteract PMD of the link is adjusting the compensating vector’s magnitude to achieve a zero-magnitude total PMD vector in the system, another is changing the vector’s direction adaptively to make the input signal align with the total PMD vector. Further, the NRZ signal DOP property degraded by PMD and the system’s BER against the change of PMD are obtained in the first experiment, also, the PMD compensation performance-degradation as the scrambling rate is increased is studied in the second experiment, in which it is concluded that the scrambling rate of polarization state has an important impact on a reliable, repeatable PMD compensation in a reasonably short time.