The stokes vector (SV) has been known since Stokes used it to represent the state of polarization (SOP) of light. While the polarization of light has been represented in the form of a SV since 1852, it has more recently found many applications in polarization management in optical communication. Our review begins with the mathematical representation of the SV. The system capacity in the optical transmission system is increased by employing a polarization diversity scheme. The rapidly changing SOP of the modulated optical signal is acquired using a Stokes vector-based direct detection (SV-DD) scheme at the receiver. A silicon photonics integrated circuit employs a SV-based polarization management scheme to control the on-chip SOP of light. Space-division multiplexed systems are a promising solution to the problem of capacity crunch. The multidimensional SV concept is employed to study signal propagation in these systems. The application of the SV in DD, silicon photonics, and space-division multiplexed systems is discussed in detail in our review. The conclusion provides a summary of the importance of SV-based polarization management in optical communication and its future prospects.
In this paper a subwavelength waveguide-to-fiber coupler based on two dimensional periodic grating is proposed. In this approach Silicon-On-Insulator (SOI) based structure is employed to couple the radiated mode field inside the core of optical fiber. Rectangular photonic integrated circuit (PIC) waveguide having standard SOI height technology of 220 nm is considered for guiding optical field inside on chip waveguide.
Detection of DNA hybridization by Silicon Nanowire Optical Rectangular Waveguide (SNORW) using full vectorial finite element method is presented. Waveguide is designed to detect DNA hybridization through change in refractive index of single strand and double strand DNA. SNORW having high surface to volume ratio with optical confinement inside low index region permits a compact sensor. Waveguide sensing characteristics such as change in effective refractive index, waveguide sensitivity and power confinement is evaluated for optimized silicon wired waveguide.
A four layered strip waveguide grown on silicon substrate and having a silicon oxynitride (SiON)
guiding film with silicon oxide (SiO2) as buffer and cover is proposed and analyzed through transfer
matrix formulation and effective index method. Dependence of polarization characteristic on
waveguide parameters such as refractive index of SiON, buffer thickness and aspect ratio (b/a) of the strip waveguide are investigated. It is shown that by selecting an optimal combination of different
waveguide parameters, a TE-mode polarizer having polarization extinction ratio of 200 dB and
insertion loss of less than 1 dB/cm can be realized.
Novel closed form formulae are derived to study crosstalk degradation due to stimulated Raman scattering
(SRS) in WDM systems employing multi-span bi-directional pumped distributed Raman amplifier (DRA). The
formulae are used to evaluate the crosstalk performance of differential phase-shift keying (DPSK) and ON-OFF keying (OOK) modulation format which are widely used in optical communication. SRS crosstalk is
further evaluated for different data rates and pulse shapes prevalent in optical data transmission. Next, crosstalk
is calculated for different pumping schemes by taking into account the launched power of bi-directional
pumped DRA. The study shows that minimum SRS crosstalk can be achieved for 40 Gb/s RZ-DPSK signal
with 33.3% duty cycle in WDM system employing backward pumped DRA.
Power penalty in N-channel WDM system due to stimulated Raman crosstalk is investigated in a typical configuration
consisting of two periodically amplified single mode fibers (SMF) by Erbium-doped fiber amplifier (EDFA) and
dispersion compensated by dispersion compensating fiber (DCF). Results show that minimum power penalty is in central
wavelength region of WDM system and inclusion of EDFA and DCF increases power penalty. Power penalty in
individual channels due to remaining N-1 channels has also been investigated. The dependence of power penalty due to
stimulated Raman scattering (SRS) on average input power, interchannel separation and bit rate of the system has also