We present a novel fiber type with a trilobal, non-circular cross section. The fiber is designed for illumination purposes with a special shape in order to form a distinct asymmetrical radiation pattern, which can be used to concentrate light on particular locations in order to cure resins or polymers but can also find its applications for illumination purposes.
In this paper we present a novel melt-spinning fabrication process for graded-index polymer optical fibers that completely avoids additional dopants for the formation of the refractive-index profile. In the presented process the meltspun fiber is rapidly cooled down so that the inner and outer parts of the fiber solidify at different speeds resulting in a density gradient. This density variation leads to a refractive-index profile without any further dopants. We present achieved results for fibers made of PMMA, and also first preliminary results for bio polymers such as TPU.
In this paper, spatial light modulation is applied to investigate the selective mode properties of multimode fibers (MMF) and MMF couplers. Spatial light modulator is applied only on the MMF input to excite a selected linearly polarized eigenmode of the MMF. At the system output the impulse and frequency response is studied. By an additional time separation of mode groups achieved during propagation in the MMF, a mode group to mode group transfer matrix of the MMF coupler can be obtained.
Proc. SPIE. 7960, Coherent Optical Communication: Components, Subsystems, and Systems
KEYWORDS: Signal to noise ratio, Digital signal processing, Light emitting diodes, Modulation, Signal attenuation, Receivers, Linear filtering, Polymer optical fibers, Analog electronics, Electronic filtering
The step-index polymer optical fiber (SI-POF) is an attractive transmission medium for high speed communication links
in automotive infotainment networks, in industrial automation, and in home networks. Growing demands for quality of
service, e.g., for IPTV distribution in homes and for Ethernet based industrial control networks will necessitate Gigabit
speeds in the near future. We present an overview on recent advances in the design of spectrally efficient and robust
Gigabit-over-SI-POF transmission systems.
In short-reach connections, large-diameter multimode fibres allow for robust and easy connections. Unfortunately,
their propagation properties depend on the excitation conditions. We propose a launching technique using a
fibre stub that can tolerate fabrication tolerances in terms of tilts and off-sets to a large extent. A study of
the influence of displaced connectors along the transmission link shows that the power distributions approach
a steady-state power distribution very similar to the initial distribution established by the proposed launching
We investigate the performance of two different all-optical wavelength conversion configurations: four-wave mixing in
highly nonlinear fiber and cascaded second harmonic and difference frequency generation in periodically poled Lithium
Niobate. Both configurations have the capability to convert phase-modulated signals with high data rates. Error free
wavelength conversion of up to 160 Gbit/s DPSK and 320 Gbit/s DQPSK data signals is demonstrated. The converter
using highly non-linear fiber can have advantages in network applications in which cascaded wavelength conversion are
requested due to its potentially higher conversion efficiency and OSNR. The Lithium Niobate converter generates no
phase distortion by wavelength conversion of phase-modulated signals. This could be useful for applications utilizing
PSK formats with 2 bit per symbol or more, like DQPSK or 8-PSK.
The concept of a nonlinear transfer function of a fibre-optic communication link is reviewed. Also an approximation of the nonlinear transfer function is introduced, which allows to define an equivalent single-span model of a dispersion-managed multi-span system. In this paper we will show its limits of validity and try to extent these limits by enhancing the theoretical model. In this respect we will discuss the impact of dispersion precompensation and show the influence of residual dispersion per span, number of spans and local dispersion on transmission systems with on-off keying and differential phase-shift keying modulation formats. This approach allows fast assessment of the performance of a given modulation format over various dispersion maps by reducing the need for extensive numerical simulations.