Single mode lasing by current injection in T-shaped QWRs

1
Single mode lasing by current injection in
T-shaped QWRs

• Sample No. 8-4-05.22C
• By Shu-man Liu
• 2006/4/8

2
Structure and composition
3
IL at different temperatures
Fig.2a I-L curves recorded when decreasing
current 2b Threshold current and differential
quantum efficiency vs. temperature
Fig.1 I-L curves recorded with increasing current
4
IV Curves at different temperatures
The derivative of the voltage versus injection
Current characteristic curve shows a high and bad
dynamic series resistance at 5K.
5
Lasing spectrum at 40K
6
EL spectrum at 5K
With increasing injection current, a new EL peak
at high energy appears, which is attributed to
emission from doped layer compared with microEL
and EL imaging results.
7
Lasing peak energy vs. T
The lasing peak red-shifts with increasing
temperature. The solid line in Fig.(b)
represents the temperature dependenceof GaAs
band-gap energy which wasshifted to fit the QWR
peak energies. Thus, the red-shift is due to the
band-gapshrink of GaAs with increasing
temperature.
8
Lasing mode hopping
The mechanism of modeis not understand.