Below is an example of some simple modelling, using EDFA Design_LITE, with M-12/980/125 incorporated in an amplifier for a 'metro' type application. The absorption and gain curves for M-12/980/125, SD188 are shown below along with the absorption curve in the 980 nm window.

These parameters form part of an encrypted data set that can be loaded into the software model. The software has an advanced graphical user interface which has amplifiers based on a number of templates, the simplest of which being that shown below for a single stage amplifier.

Each component can be individually selected and the properties for that component uniquely set. The pumps can be individually set for output power and wavelength and switched on or off as required.

The encrypted file can be loaded and the gain length can be defined and set as a variable, if required.

The model is run and a large range of parameters are generated as output files. The model has an 'OSA tool' which enables the optical spectrum at any point along the amplifier to be viewed.

For illustrative purposes the model was run with a 3 metre gain length of M-12/980/125 with 80mW of forward pump at 980 nm. The counter propagating pump was turned off. Both isolators were assigned 0.5 dB of loss and the input pump coupler was assigned 0.3 dB of loss. The output coupler was effectively removed by assigning 0 dB of loss. The output reflector does not contribute to the optical system in this example.

The output and noise figure were calculated as below.

The results show that a 3 metre gain length can be used for amplifying a single 1mW input signal across the wavelength band 1530 -1560 nm to produce an output of +14 dBm. The associated noise figure is less than 4.5 dB.