摘要:
The present invention propose to use an optical multiplexer associated with an optical clock as a wavelength converter. Each RZ coded tributary will be carried by a single wavelength (channel) passively interleaved with the others without interferometric interaction hence achieving a not necessarily perfect OTDM. This input data stream as optical data signal composed of different wavelengths is then launched on at least one data access of said optical multiplexer used as a wavelength converter. An optical clock at the desired bit-rate is launched on the probe access of said optical multiplexer synchronously to the multi-wavelength data stream. At the output, the initial clock wavelength is converted on data signal using the gain conversion property of the optical multiplexer. In such a way, a data stream of substantially higher bit-rate is obtained while due to a very precise synchronization a lost of data is minimized.
摘要:
The invention relates to an optical fiber transmission system using soliton signals with wavelength division multiplexing in which the wavelengths, &lgr;1 to &lgr;n, of the various channels of the multiplex are selected in such a manner that at least one point of the transmission system, the difference between the bit times of any two channels of the multiplex is substantially a submultiple T/N of the clock period. The invention proposes placing a synchronous modulator at said point to modulate the soliton signals at a frequency N/T which is a multiple of the soliton clock frequency 1/T. In a frequency allocation scheme that ensures that the bit times of the channels are synchronous at an interval ZR, this makes it possible to modulate all of the channels at intervals that are submultiples of ZR by using modulation frequencies that are multiples of the clock frequency.
摘要:
An optical module advantageously uses optical conversion fibers not only for a single channel but for sets of channels that are, in a specific way, selected from a multi-channel wave division multiplex (WDM) grid. The sets of channels are defined such that four wave mixing is negligible or has a negligible effect. The optical module has a demultiplexer, a multiplexer, and parallel optical conversion fiber portions that are arranged between the demultiplexer and the multiplexer. Each of the parallel optical conversion fiber portions has a specific dispersion map and transmits a different set of channels of the multi-channel WDM grid. These channels are regularly spaced from each other.
摘要:
To delay optical signals precisely and continuously in a very small dynamic range, a device for applying a time-delay to optical signals includes a first phase modulator to receive an input optical signal carried by an original center wavelength and to apply a first stage of phase modulation to the carrier wave of the input signal to supply a first intermediate signal carried by a modified center wavelength, a delaying dispersive member having chromatic dispersion to receive the first intermediate signal and to supply a second intermediate signal, and a second phase modulator to receive the second intermediate signal and to apply a second stage of phase modulation to the carrier wave of the second intermediate signal to supply an output signal carried by the original center wavelength. Applications include optical telecommunication systems, in particular converting wavelength division multiplexed signals into time division multiplexed signals and regenerating wavelength division multiplexed signals.
摘要:
A wavelength converter for binary optical signals includes an interferometer structure (110) for generating an output signal by modulating a received local signal (LS) according to the modulation of a fUrther received first input signal (IS 1). When such interferometer structures (110) are operated in a standard mode it is known in the art to control the power of the input signal such that the extinction ratio of the output signal is kept minimal. The invention also controls the power of the input signals to achieve the minimal extinction ratio when the wavelength converter and in particular the interferometer structure (110) is operated in a differential mode receiving two input signals.
摘要:
An optical receiver (5) for an optical network (2) comprises a dispersion compensation module (7) for adjusting an amount of chromatic dispersion of optical signals transmitted through the optical network (2) and is characterized in that a nonlinear optical element (13) for spectral broadening of a dispersion probe signal transmitted through the optical network (2) is arranged in a measuring path (11) downstream of the dispersion compensation module (7), and a power measuring means (15) for measuring an average power of the optical dispersion probe signal over a predetermined frequency range is arranged downstream of the nonlinear optical element (13) in the measuring path (11).
摘要:
The invention relates to a wavelength converter for binary optical signals comprising an interferometer structure (110) for generating an output signal by modulating a received local signal (LS) according to the modulation of a further received first input signal (IS1). When such interferometer structures (110) are operated in a standard mode it is known in the art to provide a control means for controlling the power of the input signal such that the extinction ratio of the output signal is kept minimal. The invention provides a modified control means for also achieving the minimal extinction ratio when the wavelength converter and in particular the interferometer structure (110) is operated in a differential mode receiving two input signals.
摘要:
The invention provides a method of repairing an optical fiber transmission system using soliton signals and wavelength division multiplexing, in which the various wavelengths, &lgr;1 to &lgr;n, of the multiplex are selected to ensure that over a given interval ZR, the relative slip between the various channels is substantially equal to a multiple of the bit time, the method comprising the following steps: inserting an additional length of optical fiber in the transmission system; and compensating for the effects of said additional length on the relative slip between the various channels of the multiplex. The invention also provides apparatus for repairing such an optical fiber transmission system using solution signals with wavelength division multiplexing. The invention prevents relative slip between the channels due to inserting an additional length of fiber into the transmission system.
摘要:
The disclosure relates to an end fitting (40) for connecting a flexible pipe for transporting a cryogenic fluid, comprising thermal insulation means (65) interposed between the cold part (41) of the connecting end fitting and the rear part (51) for crimping the end of a leak proof sealed external sheath (9) of said flexible pipe.
摘要:
It is propose to use a DI-NOLM comprising an optical loop made of two spools of dispersive fibers with large effective area but of local dispersion of opposite sign and a HLN fiber in between. In this configuration according to the invention, the input optical signal needs to be initially chirped. A nonlinear phase shift is then generated between both counter propagating optical fields inside the HNL as the consequence of the peak power imbalance. Advantageously, it is possible to process RZ or RZ/DSPK with a rather large shape at half-way taking even more than 65% of bit time. This can be achieved without any alteration of the optical regeneration. Moreover, in this configuration by using the method according to the invention, the compensation dispersion is realized inside the DI-NOLM, and so it is not necessary to add a compensating dispersion state at this interferometer.