Control and supervision of semiconductor optical amplifiers for use in submarine systems

Many experiments have demonstrated the use of travelling wave semiconductor laser amplifiers (TWSLA) as linear repeaters. All of these experiments were under strictly controlled environments to eliminate gain variations due to temperature and signal state fluctuations. However, few authors have addressed the real problems associated with the short term application of the TWSLA technology. Of particular importance are the practical gain variations present in a TWSLA system. In this paper, the authors describe the operation of a simple gain control technique requiring no additional optical components, which can easily be extended to provide supervisory facilities.