Optical Carrier transmission rates

About: Optical Carrier transmission rates is a research topic. Over the lifetime, 2463 publications have been published within this topic receiving 33293 citations.

Uplink downlink construction for radio frequency optical fiber transmission system and method for providing light carrier to uplink

Abstract: The invention relates to an uplink, downlink construction of radio-frequency optical fiber transmission system, and a method for providing an optical carrier to the uplink. An uplink downlink construction of radio-frequency optical fiber transmission system is proposed, and an optical carrier filter is provided in the downlink construction. A double band signal having an optical carrier is generated by a Mach-Zhender modulator, wherein the optical carrier is suppressed using the optical carrier filter, so as to improve modulation degree of the signal. And an optical signal generated by the SBS having frequency lower than the optical carrier frequency 11GHz is provided as optical carrier. The invention is simple in construction, easy to implement, stable in performance, low in cost, easy to apply and propagate.

Optical circuits for equalizing group delay dispersion of optical fibers

Abstract: Optical circuits are synthesized for equalizing the group delay dispersion of single-mode fibers. The transfer function of the equalizing circuits are given by Chebyshev polynomials of the second kind. The various realization methods for the group delay equalizer are shown, including periodic structures using birefringent crystals, birefringent fibers, and Mach-Zehnder interferometric planar optical circuits. An optical equalizer employing TiO/sub 2/ birefringent crystals was fabricated and evaluated by using an optical network analyzer, which operates by making modulation-envelope phase and amplitude measurements while scanning the optical carrier frequency. The measured optical equalizer characteristics show excellent agreement with the simulation analysis. The effectiveness of the equalizer for substantial reduction of the dispersion penalty for a 10 Gb/s signal transmitted over 30 km of normal dispersion fiber was demonstrated. The periodicity of the equalizer results in periodic dispersion-free bands, and hence, the equalizer is suitable for use in future multichannel FDM systems. >

Optical transmission method with reduced sensitivity to dispersion, transmission device and system for implementing this method

Abstract: An embodiment of said method comprises coding a binary information sequence (SI) to be transmitted, in the form of a second binary signal (SM) by differential coding; filtering the second binary signal (SM) to obtain a duobinary signal (SMF) having three significant values (-a, O±e, +a) and a smaller bandwidth; modulating an optical carrier in accordance with the values taken by the filtered signal (SMF), by providing the modulated carrier with a maximum amplitude to represent the maximum value (+a) and the minimum value (-a) of the duobinary signal (SMF), by offseting the phase of the modulated carrier by υ1 and by υ2 = υ1 + 180° respectively; and providing the modulated carrier with a minimum amplitude to represent the values (O±e) which are close to O. The method of the invention is suitable for long distance fibre-optics transmissions.

Method and apparatus for the transmission fault detection in an access network

Abstract: An optical network unit (ONU) interconnected by passive optical network (PON) equipment to an optical line terminal (OLT) is identified using secondary modulation of the optical carrier to impress an identifier of the ONU onto the carrier. This resolves a recurring ONU failure mode detection problem caused by failure of a laser driver that causes the ONU to be stuck in an on state.

Optical Wireless OFDM System on FPGA: Study of LED Nonlinearity Effects

Abstract: Nonlinearities can drastically degrade the performance of OFDM (orthogonal frequency division multiplexing) based optical wireless (OW) communication systems using intensity modulation (IM) of the optical carrier. The light emitting diode (LED) transfer function distorts the signal amplitude and forces the lower signal peaks to be clipped at the LED turn-on voltage (TOV). Additionally, the upper signal peaks can result in optical output degradation. The induced distortion can be controlled by optimizing the bias point (BP) of the LED and/or backing-off the signal power modulating the LED. In this paper, the obtained experimental results using a hardware demonstrator for OW OFDM transmission based on field programmable gate array (FPGA) and off-the-shelf analog components are presented. The conducted measurements for the bit-error performance focus on determining the optimum BP and optimizing the OFDM signal amplitude to obtain best performance. In this context, the experimental bit-error ratio (BER) is obtained as a function of the LED BP and the RMS (root mean square) OFDM signal across the LED.