Introduction to optical telecommunications (without lab)

This lab covers the key points of a complete optical telecommunication system:
- its transmission (modulable laser sources),
- a means of transmission (optical fiber),
- its reception (photodiodes)
- two different systems of wavelength multiplexing and demultiplexing (using diffraction gratings and dichroic filters).

Topics covered:
- Signal transmission through optical means
- Wavelength multiplexing
- Wavelength demultiplexing   

Principles and objectives:
- Signal transmission through optical means:
Modulable laser diodes are used to transport a signal. Since the sources have different wavelengths, it is possible to combine them at the fiber input (multiplexing) and separate them at the ouExperimentut (demultiplexing).
- Wavelength multiplexing:
A diffraction grating deflects the beam of the red laser diode at a different angle than that of the blue laser diode. This property is used to inject both signals into the same fiber. It is also possible to simply use the fiber's high numerical aperture to directly inject the beams of the 2 laser diodes with the appropriate incidence angle.
- Wavelength demultiplexing:
At the fiber ouExperimentut, the same diffraction grating angularly separates the signal carried by the red light from that carried by the blue source. Another method is to use blue and red color filters to isolate and separate the signals.

Composition:
▪ 1 adjustable red laser (ref.201004)
▪ 1 adjustable blue laser (ref.204598)
▪ 2 phototransistors SFH-300
▪ 3 simple component holders (ref.202439)
▪ 2 fiber supports with SMA Clix bases on rod (ref.204727)
▪ 1 thin blade holder on rod (ref.202448)
▪ 1 Paton network 600 lines/mm (ref.202343)
▪ 2 converging lenses, f= + 50 mm (ref.202273)
▪ 2 dichroic filters: yellow and blue (ref.204023+204020)
▪ 1 plastic SMA fiber – 2 m (ref.202729)
▪ 1 set of experiments instructions