Narrow spectral linewidth(<100kHz) laser diodes are required in coherent optical communication systems(PSK systems) and optical measurement systems. The linewidth characteristics for laser diodes have been investigated, and it has become obvious that the spatial hole burning phenomenon limits the linewidth reduction in DFB lasers1). On the other hand, in DBR lasers, the spatial hole burning phenomenon is less effective. Therefore DBR structure is thought to be promising to obtain an extreme narrow linewidth operation.
© 1991 Optical Society of AmericaPDF Article