High speed direct modulation of semiconductor lasers

Direct modulation of the injected current still represents an attractive and inexpensive technique for encoding information in the output of a semiconductor laser. The growing requirements in volume of information to be transmitted and their conflict with the progressive, and rapid, degradation of the signal at high speeds have made this simple technical solution less and less attractive. A brief analysis of the sources of the problem is offered. A viable and inexpensive way of improving DM's performance is discussed. High quality signals are predicted at data transmission speeds that exceed by over an order of magnitude those obtainable with DM.