Coexistence of excitonic lasing with electron-hole plasma spontaneous emission in one-dimensional semiconductor structures

We report that excitonic lacing gaits coexists with spontaneous optical emi ssion characteristic of an electron-hole plasma in highly photoexcited one- dimensional semiconductors. The experiments probe quantum T-wire laser stru ctures optimized for high photoexcitation. Evidence of dense electron-hole plasma is clearly seen in the spontaneous recombination measured when lacin g emission displays distinct excitonic character. These findings differ str ikingly from those in higher dimentional semiconductors, and offer insights on optical processes considered by recent theories of dense electron-hole plasmas. (C) 2001 Published by Elsevier Science Ltd.