| 摘要 |
In the field of optical communications, electro-absorption (EA) modulators (12) can be used to modulate electromagnetic radiation (50) to generate a modulated signal (52). A change in temperature of the EA modulator (12) during operation can change the extinction ratio and average power of the modulated signal (52). In order to maintain the extinction ratio and average power of the modulated signal (52) it is known to monitor the temperature of the EA modulator (12) and generate a feedback signal to cool or heat the EA modulator (12) as appropriate. Consequently, the present invention provides a control loop apparatus (10) for maintaining a constant extinction ratio and an average power of the modulated signal (52) without the need for the monitoring of the temperature of the EA modulator (12) and without the need to heat or cool the EA modulator (12). <IMAGE> |
