摘要:
A method is disclosed of reconfiguring a ring optical network made using a single optical fiber (100). A traffic concentrator (120) and stations (140) are optically connected to the fiber. The concentrator sends a light signal to and receives a light signal from both ends of the fiber using two groups of wavelengths (110, 150) in order to be able to communicate with all the stations. When the network is established, a virtual break (170) is created between two stations. If a real break is detected in the optical fiber, then the virtual break is shifted until it coincides with the real break, thereby enabling traffic to be re-established between the concentrator and the stations. Each station is equipped with a three-state optical switch (400) for changing the direction of the light signals.
摘要:
The device includes a decision circuit (6a) for providing, by comparing the amplitude of a received modulated signal (Sr) to a decision threshold (Vth, Th), a binary signal (Sb) with two states respectively representing first and second binary values that respectively correspond to low and high values of the received signal. A counting module (12) activated during successive time periods calculates a differential numerical value (DN, SDN) representing the algebraic difference between the two numbers of bits of the binary signal that respectively have the second binary value and the first binary value. At the end of each time period, an adjustment module (15) increases or decreases the threshold value (Vth, Th) by an increment (Dth) according to whether the sign (SDN) of the difference is respectively positive or negative. Application in particular to systems for transmitting digital data at high bit rates over optical connections.
摘要:
An optical multiplexer device (D) is dedicated to inserting/dropping optical resources into or from an optical transmission line comprising incoming and outgoing optical fibers (F1, F2). The device (D) comprises: i) first coupler means (C1) having an inlet and an outlet connected respectively to the incoming optical fiber (F1) and to the outgoing optical fiber (F2), and an inlet/outlet (1) coupled to the inlet and the outlet; ii) both-way multiplexer/demultiplexer means (2) defining at least two internal channels (3) each connected to a primary inlet/outlet (ES1) coupled to the inlet/outlet (1) and comprising at least two secondary inlets/outlets (ES2) each connected to an internal channel (3); and iii) at least two send and/or receive modules (R, T) each coupled to a secondary inlet/outlet (ES2) by both-way light guide means (4′) fitted with optical processor means (5, 6) capable, on order, of taking up at least a reflection state reflecting an optical resource to the secondary inlet/outlet (ES2) that delivered it and a transmission state enabling an optical resource to be transferred between a send and/or receive module (R, T) and the associated secondary inlet/outlet (ES2), the optical power that is transmitted or reflected optionally being adjustable.
摘要:
An optical device that measures and dynamically compensates power loss variations in an optical fiber based on supervisory signals. An injector injects supervisory signals having a predefined optical power downstream of the fiber entry end and a detector extracts the supervisory signals at the exit end of the fiber to detect their optical power. Based on the detected optical power and the predefined optical power, the optical power loss of the supervisory signals in the fiber is determined. The optical power loss and the nominal power loss in the fiber are compared to determine a variation in the power loss in the optical fiber. A controller coupled to the detector and to the exit end of the fiber modifies the power of primary signals delivered by the exit end of the fiber as a function of the detected variation in power loss.
摘要:
In particular for selectively dropping and/or inserting channels of a wavelength division multiplex, while minimizing losses, the apparatus includes n stop filters and optical switching means provided with n+1 inlet ports of ranks 0 to n, and n+1 outlet ports of ranks 1 to n+1, as well as a set of waveguides making it possible to couple each outlet port selectively to one of said inlet ports of lower rank. Each filter is provided with first and second opposite ports coupled respectively to an associated outlet port and to an associated inlet port of the same rank. Application to optical transmission, in particular for performing routing operations.
摘要:
A device for erasing overhead modulation of an optical signal, wherein said optical signal is injected into an optical device able to modulate the optical signal (for example a semi-conductor optical amplifier driver by a bias control) and for which one an automatic gain control does not need to detect the residual overhead modulation, is characterised in that said bias control means applies to said amplifier a compensation voltage presenting a modulation out of phase with respect to said overhead modulation, and in that modulation index of said compensation voltage is (substantially) proportional to the modulation index of said optical signal.