Laser diodes for CATV

Distribution of cable television signals over fiber optic links has expanded rapidly over the past five years. Direct modulation of an optical source with an ever-increasing number of subcarrier multiplexed, amplitude modulated television channels remains the most common scheme for encoding these video signals. The simplicity of an analog optical transmission system is balanced against the stringent linearity specifications placed on the optical source, typically a 1.3 /spl mu/m index-guided distributed feedback (DFB) laser. The paper reviews development of high performance DFB lasers for transmission of analog CATV signals, focussing upon intrinsic impairments to linearity and various approaches to device optimization.