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.

Experimental Demonstration of 1.25-Gb/s Radio-Over-Fiber Downlink Using SBS-Based Photonic Upconversion

Abstract: We experimentally demonstrate a radio-over-fiber downlink system using a stimulated Brillouin scattering (SBS)-based photonic upconversion technique. The Brillouin selective amplification characteristic of SBS is incorporated to generate the 11-GHz band radio-frequency (RF) carrier. The dual-electrode Mach-Zehnder optical modulator, which is used to carry the broadband data in the optical carrier instead of the optical sideband, is adopted along with the SBS-based carrier generation setup. To vindicate the broadband capabilities of the proposed scheme, 1.25-Gb/s pseudorandom bit sequence data is carried in the optical carrier. Error-free operation of the 1.25-Gb/s downlink is achieved without critical power penalties after the 13-km fiber transmission.

Multiple simultaneous optical frequency measurement

Abstract: A signal processing apparatus for providing concurrent electrical frequency measurements of multiple, time-coincident signal inputs. In one embodiment of the present invention, an input signal is received that contains a plurality of individual signals independent of each other in frequency, phase, and electrical amplitude. A power splitter splits the input signal into two separate input signals. A delay line introduces a time delay to one of the two separate input signals. Two Bragg cells within a channelized optical phase measurement (COPM) device modulates two optical carrier signals with the delayed and non-delayed input signals, respectively, separating the modulated delayed and non-delayed input signals into multiple time-concurrent frequency channel signals. Upon exiting the Bragg cells, the two optical beams interfere spatially to develop an interference pattern along the phase and frequency channel number axes of a photodetector array. The resulting spatial intensity pattern phase variation is decoded to provide coarse frequency, phase, and amplitude measurements. A frequency encoder receives the photodetector outputs, corrects phase and amplitude data offsets, and converts phase to fine frequency. Finally, the frequency formatter concatenates coarse to fine frequency for readout.

Photonic Ultrawideband Pulse Generation With HNL-DSF-Based Phase and Intensity Modulator

Abstract: We propose and experimentally demonstrate a photonic ultrawideband (UWB) pulse (monocycle and doublet) generator based on a highly nonlinear dispersion-shifted fiber (HNL-DSF). The pulsed pump, located in the anomalous group-velocity dispersion regime of the HNL-DSF, performs as both an intensity and a phase modulator in our scheme. We experimentally prove, for the first time to the best of our knowledge, that the UWB doublet pulse can be generated when the optical carrier is located at the center of a narrow tunable filter's passband. Furthermore, the encoded doublet signal, fully compliant with the Federal Communications Commission (FCC) regulations, is transmitted at 950 Mb/s through a 25-km single-mode fiber without introducing any obvious pulse distortion.

Photonic Generation of Triangular-shaped Waveform Based on External Modulation

Abstract: We present a novel approach for triangular-shaped waveform generation by applying optical single sideband (OSSB) modulation and optical carrier suppression (OCS) modulation to an input signal. Firstly, an OSSB modulated signal consists of an optical carrier and +1st-order sideband, is initially generated with a dual-drive Mach-Zehnder modulator (DD-MZM1) driven by a quadruple frequency RF signal. By tuning the amplitude of the RF signal and the bias of the DD-MZM1, the power ratio between the carrier and the +1st-order sideband is controlled as 19 dB. These two components are then transmitted to a DD-MZM2 which is driven by a fundamental frequency. After OCS modulation, four sidebands are existed in optical spectra of the modulated signal. By utilizing a fiber Bragg grating (FBG) to remove the undesired sideband, an output signal that features a triangular-shaped waveform is finally achieved.

A High Spectral Efficiency Radio Over Fiber Link Based on Coherent Detection and Digital Phase Noise Cancellation

Abstract: An approach to transmitting two independent microwave vector signals on a single optical carrier with one polarization state based on coherent detection and digital phase noise cancellation is proposed and experimentally demonstrated. At the transmitter, two independent microwave vector signals are modulated on an optical carrier via a dual-drive Mach-Zehnder modulator (DD-MZM). The modulated optical signals are transmitted over a single-mode fiber (SMF) and sent to a coherent receiver. At the receiver, the optical signals are detected where a local oscillator (LO) optical wave generated by a second free-running laser source is also applied. To recover the two microwave vector signals, a novel digital signal processing (DSP) algorithm is developed and applied to eliminate the joint phase noise terms from the transmitter and the LO laser sources as well as the unstable offset frequency between the two laser sources. An experiment is performed. The transmission of two independent 16 quadrature amplitude modulation (16-QAM) microwave vector signals at 4 GHz with a symbol rate of 1 GSymb/s over a 9-km SMF is demonstrated. The transmission performance in terms of error vector magnitudes (EVMs) and bit error rates (BERs) is also evaluated.