Coherent optical transmission systems for data rates above 100 Mb/s require single-mode laser sources with linewidths in the range of 100 kHz to 10 MHz. This can be achieved by using an external cavity configuration for the laser. This paper describes the use of fiber cavities with both Fabry-Perot and distributed feedback (DFB) lasers to provide sources to meet these requirements. Fiber cavities are attractive because they are Insensitive to acoustic disturbances and can be assembled into a small temperature controlled package.
© 1987 Optical Society of AmericaPDF Article