| 摘要 |
A transmitter for multiplexing three optical channels at different wavelengths has (a) first, second and third laser diode means delivering linearly polarized optical beams at respective wavelengths lambda 2, lambda 3 and lambda 4 which are mutually different; (b) an assembly located in the path of the light of wavelength lambda 2 emitted by said first diode means and including a plate which is substantially quarter-wave for the wavelength (2 lambda 2- lambda 4), a filter having a band pass centered on wavelength lambda 2, a plate quarter-wave which is substantially for wavelength lambda 4 and a polarizer, the first diode means being oriented so that its beam is transmitted by the polarizer. A first light beam combiner directs light from said third diode means onto the polarizer along a direction of 90 DEG from the direction of the beam of wavelength lambda 2 and with the same polarization direction, so that the beam of wavelength lambda 4 is reflected towards said filter. A second combiner directs the light from said second diode, having wavelength lambda 3 intermediate between lambda 2 and lambda 4, onto the polarizer in a direction opposite to that of the light beam of wavelength lambda 4 and with a polarization of the same direction, so that the light of wavelength lambda 3 is reflected along a path coaxial with the output path of the light having wavelength lambda 2 and lambda 4. More than three channels may be combined.
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