摘要:
An optical communication link with correction of non-linear effects comprises an optical fiber transmission line subject to chromatic dispersion and non-linear effects and correction means for limiting the disadvantageous consequences of this dispersion and/or these non-linear effects. The correction means comprise at the output of the transmission line a dispersion compensator adapted to apply dispersion in the opposite direction to and of lower absolute value than the dispersion due to the transmission line.
摘要:
Optical pulses carrying information to be conveyed are routed, for each pulse, by the intensity of the pulse. The pulses may be solitons. The invention is particularly applicable to long distance communications.
摘要:
An amplifying fiber is connected at both ends to two respective pump-forming semiconductor lasers. The connections are made via two pump injection fibers and two multiplexers. According to the invention, each of the two pump injection fibers includes a respective photorefractive filter constituting a portion of the resonant cavity of the associated pump, and serving to separate the spectrum bands of the pumps. The invention is particularly applicable to optical fiber telecommunications networks.
摘要:
A link using spectrum multiplexing, in which link an amplifying fiber amplifies a plurality of multiplexed carrier waves. The invention makes it possible to maintain a flat spectrum distribution of the gain of the amplifying fiber when the number of carrier waves varies. For that purpose, light that is amplified by the amplifying fiber and that is independent of the carrier waves is servo-controlled in power. The light is constituted by a reverse amplified spontaneous emission. After being filtered in a filter and detected by a photodiode, the light controls the power supplied to two laser diodes for pumping the fiber. The invention applies in particular to implementing optical transmission networks.
摘要:
The source includes an electro-absorption modulator receiving a continuous light wave supplied by a laser emitter 10. The characteristic response curve of the modulator has a threshold so that the modulator transmits an optical pulse having a duration which is less than the duration of an electrical control pulse which is applied to the modulator by a control generator. Soliton-type optical pulses obtained in this way are transmitted via a line fiber to a receiver. Application to optical transmission.
摘要:
A photodiode (26) receives an optical input signal (P1) and an internal optical signal (P2) and supplies in response thereto an internal electrical signal (I2), which in turn controls a laser (4) which effects amplification and supplies the internal optical signal and an output signal (P3). The feedback loop formed by this photodiode and laser leads to a strong non-linearity in the variation of the output signal as a function of the input signal. The invention is useful especially in optical fiber telecommunications systems.
摘要:
A femtosecond dye laser comprises a dye amplifier assembly (30) pumped by a mode-locked neodymium YAG laser (35) operating with frequency doubling. The main dye laser cavity as defined on one side of the amplifier assembly (30) by a linear prism structure (11 and 14) leading to an outlet mirror (15), and on the other side of the amplifier assembly by an assembly (20) constituting an anti-resonant mirror disposed about a saturable absorption device (40). An error signal is tapped by leakage from one of the mirrors (22) and is spectrally analyzed and compared with a reference wavelength (at 50) enabling a high tension amplifier (60) to be controlled to act on a piezo-electric stack (19) in order to fix the position of the outlet mirror (15) so as to adjust the optical length of the cavity as a function of the spectral characteristics of the pulses it produces.