||Double threshold behavior in a resonance-controlled ZnO random laser
Niyuki, Ryo Fujiwara, Hideki ,
Nakamura, Toshihiro ,
Ishikawa, Yoshie ,
Koshizaki, Naoto ,
Tsuji, TakeshiSasaki, Keiji
, p.36101 , 2017-03 , American Institute of Physics (AIP)
We observed unusual lasing characteristics, such as double thresholds and blue-shift of lasing peak, in a resonance-controlled ZnO random laser. From the analysis of lasing threshold carrier density, we found that the lasing at 1st and 2nd thresholds possibly arises from different mechanisms; the lasing at 1st threshold involves exciton recombination, whereas the lasing at 2nd threshold is caused by electron-hole plasma recombination, which is the typical origin of conventional random lasers. These phenomena are very similar to the transition from polariton lasing to photon lasing observed in a well-defined cavity laser.