Optical amplifiers increase the range of optical transmission systems. The amplification takes place on a purely optical level and without the signal having to be converted into an electrical signal in between. Depending on the physical method of amplification, there are 2 amplifier types in the MICROSENS portfolio:
in erbium-doped fiber amplifiers (EDFA amplifiers), the optical fiber is doped with erbium over a certain length. This fiber section is then optically pumped with the help of a semiconductor laser. The EDFA amplification method only works in the C-band, which is why CWDM signals cannot be amplified.
The MICROSENS EDFA amplifiers take the concept of variable gain into account. The basic family can be used as booster (amplification at the starting point), as pre-amp (amplification at the end point) and as inline amplifier (amplification on the line). The entire MICROSENS EDFA amplifier family can be configured either according to the principle of "constant output power", so that the output signal always has the same amount, or according to the principle of "constant gain", so that the amplification amount remains unchanged. Each amplifier has an internal optical supervisory channel (OSC) at 1510nm, which is necessary for the manageability of the amplifiers. The output power values of the respective amplifiers are also transmitted via this channel, which are used to automatically compensate for fiber aging. The EDFA amplifiers are also available for use in extreme conditions (extended operating temperature range from -40 to +65°C), with these versions additional air conditioning at the direct place of use become obsolete.
Raman amplifiers use so-called Raman dispersion. When an optical pump wave (high intensity) is irradiated, the photons are scattered at the silicon dioxide molecules in quartz glass fibers. A part of the energy is converted into phonons and the rest is scattered as photons of lower energy. This process initially takes place spontaneously, but can also be stimulated by the signal wave to be amplified. This is called stimulated Raman scattering. The advantages of Raman amplification are that, in addition to the C-band, it can also be used in the L-band and that, compared to EDFA amplification, it produces a better signal-to-noise ratio (OSNR) during amplification. This is of particular importance when multiple amplification is used to convert very long distances.
The MICROSENS RAMAN amplifiers are designed for long distances, so that intermediate stations can be dispensed with. With the MICROSENS RAMAN amplifier, particularly large output power values can be achieved, whereby the signal-to-noise ratio is very favorable.
The portfolio is completed by Remote Optical Power Amplification (ROPA) systems, with which distances of up to 450 km can be realized (with savings on active inline components). The basic product of this solution is the absolutely passive Remote Optical Amplifier (ROA), which is spliced into the fiber along the line and fed via the active Remote Amplifier Pump (RAP) installed at the terminal ends.