Large spontaneous emission factor confirmed in CW lasing microdisk injection lasers

Microdisk lasers are suitable for spontaneous emission control due to a high Q lasing mode with an ultra-small volume. However, the clear evaluation of spontaneous factor C is difficult for pulsed and/or photo-pumped devices due to the necessity of a wide range fitting of light-current characteristic from far below threshold. Recently, we have achieved CW lasing in GaInAsP devices with the record low threshold of 40 /spl mu/A. In this study, we fabricated 1.56 /spl mu/m GaInAsP compressively-strained QW microdisk injection lasers and observed some clear evidence of large C factors in the lasing characteristics.