Realization of a high-power flat-gain ASE source with C/L/C plus L band selection via embedded software control

Amplified Spontaneous Emission (ASE) sources operating in both C-band and L-band generally use separate setups for each band. Using separate setups for C and L-bands increases design complexity and cost while using a single setup deteriorates the flatness of the output gain spectrum. This work presents the design and implementation of a flat gain ASE source that can operate in C-band and L-band separately or combined with only a single optical setup for all bands. The optical setup designs are first optimized in a simulation environment for the required length of Erbium Doped Fiber (EDF), the number of pump lasers, pump powers, and pump wavelengths. Then, an optical management board containing a multi-laser control driver and embedded software algorithm is developed to achieve flat gain and separate operation of C/L/C + L bands. With this management board, the lasers on the optical setup can be controlled and the output spectrum can be adjusted to the desired optical power and ripple without requiring any external components such as optical switches/optical filters. The developed ASE source offers bandwidths of 36 nm (1524-1560 nm), 44 nm (1560-1604 nm), and 80 nm (1524-1604) for the C, L, and C + L bands, respectively, while providing a constant output power of 30 mW and a 3 dB power ripple across all bands. As a result, to our knowledge, for the first time in the literature, an ASE source has been developed without an optical component, with band selection via a management board, adjustable optical power and ripple, and at a very low cost compared to the market.