We investigate the features of the self-deflection of the screening-photorefractive spatial soliton and the influence of
first-order and higher-order space charge field on the propagation characteristics by considering the diffusion effect, The
results show that the center of the optical beam moves on a parabolic trajectory; As to the highter-order space charge
field, the self-bending process is further enhanced by a factor that varies cubically with the applied field. The numerical
study shows that the bending distance of the soliton beam center increase, reaching its maximum value at the
characteristic temperature. Numerical investigations show that the in-phase interaction will result in the separation of two
solitons from each other, As for the anti-phase interaction side, two solitons separated each other and delect simultaneously
to the same side.
In the paper, we have proposed a structure with only one photonic crystal (PC) micro-cavity side-coupled to a PC
one-way waveguide to generate strong on-resonance optical delay. According to the coupled mode theory (CMT),
the resonator system can maintain a 100% transmission spectrum throughout the complete resonant bandwidth,
which is also demonstrated by the numerical results calculated by the finite element method (FEM). As a temporal
Gaussian pulse is launched, the simulation results show that the device introduces a strong pulse delay while
maintaining total transmission efficiency within the resonant bandwidth, and the resonator structure may be of great
significance for making delay lines in optical buffer applications.
We design a highly efficient channel drop filter (CDF) with only one channel drop micro-cavity based on photonic
crystal (PC) one-way waveguide. By means of the new nature of waveguide-cavity interaction, over 95% channel drop
efficiency can be realized in the structure. Some multichannel drop filters with high drop efficiencies are also engineered
based on such the structure. These numerical results are all calculated by using the finite element method (FEM), which
agrees well with the theoretical analysis result.
Quantum Key Distribution (QKD) networks allow multiple users to generate and share secret quantum keys with
unconditional security. Although many schemes of QKD networks have been presented, they are only concentrated on
the system realization and physical implementations. For the complete practical quantum network, a succinct theoretic
model that systematically describes the working processes from physical schemes to key process protocols, from
network topology to key management, and from quantum communication to classical communication is still absent. One
would hope that research and experience have shown that there are certain succinct model in the design of
communication network. With demonstration of the different QKD links and the four primary types of quantum
networks including probability multiplexing, wavelength multiplexing, time multiplexing and quantum multiplexing, we
suggest a layer model for QKD networks which will be compatible with different implementations and protocols. We
divide it into four main layers by their functional independency while defining each layer's services and responsibilities
in detail, orderly named quantum links layer, quantum networks layer, quantum key distribution protocols process layer,
and keys management layer. It will be helpful for the systematic design and construction of real QKD networks.