摘要:
An optical system dynamically measures power loss in an optical fiber (2) having an entry end (E) adapted to receive optical signals and an exit end (S) adapted to deliver the signals. The system comprises modulation means (4) upstream from the entry end (E) and adapted to modulate the amplitude of the optical signals with a low-frequency modulation signal having a modulation index inversely proportional to the input power (Pe) of the optical signals, and detection means (7) downstream from the exit end (S) and adapted to extract from the modulated optical signals primary information representative of the output amplitude of the modulation signal and to deduce from the primary information secondary information representative of a variation in the power loss in the fiber.
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:
An optical system is dedicated to dynamically measuring power loss in an optical fiber (FO) having a first end (E1) and a second end (E2) respectively adapted to receive and to send primary optical signals. The system comprises injection means (3) adapted to inject supervisory signals into the second end (E2) of the optical fiber (FO) at a selected optical power and detection means (5) adapted to extract the supervisory signals at the first end (E1) of the optical fiber (FO) in order to determine their optical power and to deduce therefrom and from the selected optical power primary information representative of the optical power loss of the supervisory signals in the optical fiber (FO), and where applicable to compare the primary information to a value representative of a nominal power loss in the optical fiber (FO) in order to supply secondary information representative of a variation of the power loss in the optical fiber.
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 for an optical transmission line comprising an upstream fiber (F1) and a downstream fiber (F2). The device (D) comprises: i) first and second OMADs (M1, M2) each having a first primary inlet/outlet (EP1, EP3) connected to the upstream fiber (F1) or to the downstream fiber (F2), and to L internal demultiplexing channels (VI11, VI21) connected to L first secondary inlets/outlets (ES11, ES21), and a second primary inlet/outlet (EP2, EP4) connected to M internal multiplexing channels (VI12, VI22) connected to M second secondary inlets/outlets (ES12, ES22) connected to M or N send or receive modules (Tx, Rx); ii) L external coupling channels (VEC) interconnecting the L first secondary inlets/outlets (ES11, ES21), and each fitted with a respective VOA (MT) capable, on order, of placing itself in a through state or in a blocking state for allowing or preventing an optical resource to be transferred between the first and second OMADs (M1, M2); and iii) an external drop channel (VEE) connected to the upstream fiber (F1) and to the primary inlet/outlet (EP4) of the second OMAD (M2), and an external insert channel (VEI) connected to the downstream fiber (F2) and to the second primary inlet/outlet (EP2) of the first OMAD (M1).
摘要:
The present invention relates to the field of optical telecommunications networks, and more particularly to a method and to devices for backing up a ring optical telecommunications network. The method of the invention corresponds to a method of backing up a ring optical telecommunications network including a traffic concentrator (1) and a communications node (N3) interconnected by an optical fiber (2) (s1, s2) transported in the fiber and addressed to the node. The method of the invention comprises the following successive steps: while the network is being set up, a step of creating a virtual break (C) between the concentrator and the node; and when an at least partial real break in the fiber is detected that limits or interrupts the transmission of the signals to the node, a step of displacing the virtual break so that it coincides with the real break so as to re-establish the reception of the optical signals by the node.
摘要:
An optical multiplexer device is dedicated to inserting/dropping optical resources for an optical transmission line comprising an upstream fiber and a downstream fiber. The device comprises: first and second OMADs each having a first primary inlet/out1et connected to the upstream or downstream fiber, and to L internal demultiplexing channels connected to L first secondary inlets/outlets, and a second primary inlet/outlet connected to M internal multiplexing connected to M second secondary inlets/outlets, connected to M send or receive modules L external coupling channels interconnecting the L first secondary inlets/outlets, and each fitted with a respective VOA capable of placing itself in a through or blocking state for allowing or preventing an optical resource to be transferred between OMADs; and an external drop or insert channel connected to the upstream or downstream fiber, respectively, and to the first primary or second primary inlet/outlet of the second or first OMAD, respectively.
摘要:
The present invention relates to a method of monitoring the transmission of optical signals including a step of inserting a monitoring signal (S) more particularly suited to monitoring the quality of service. During the transmission of optical signals each carried by a predefined wavelength defining a transmission channel (Ci), said signals are grouped onto the same fiber in a band (B) of channels. The method then includes a step of simultaneously modulating said signals grouped in the band of channels using the monitoring signal to be transmitted, so that each of the signals constitutes a carrier of the monitoring signal.
摘要:
An optical demultiplexer system for separating adjacent wavelength bands without losing inter-band channels and comprising a first filter stage (210) of relatively narrow passband and relatively high selectivity in order to extract all of the inter-band channels. The first stage is followed by a second filter stage (240) of relatively broad passband and relatively low selectivity to extract the wavelength bands delivered by the first filter stage. Such a system makes it possible to use the inter-band channels, in particular for managing the network and the wavelength bands.
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.