J. Piprek et al., MINIMUM TEMPERATURE SENSITIVITY OF 1.55 MU-M VERTICAL-CAVITY LASERS AT -30 NM GAIN OFFSET, Applied physics letters, 72(15), 1998, pp. 1814-1816
Double-fused vertical-cavity surface-emitting lasers (VCSELs) have dem
onstrated the highest temperature performance of any 1.5 mu m VCSEL, b
ut further optimization is needed to reduce their temperature sensitiv
ity, We present and analyze threshold current measurements of these de
vices between -90 degrees C and 30 degrees C stage temperature, Despit
e a zero gain peak offset from the emission wavelength at room tempera
ture, the pulsed threshold current has its minimum near -50 degrees C
corresponding to about -30 nm gain offset, This is in contrast to a co
mmon VCSEL design rule. Temperature effects on the optical gain of the
strain-compensated InGaAsP/InP active region are found to be the main
cause for the disagreement. A design rule modification is proposed. N
umerical simulation of an optimized 1.55 mu m VCSEL shows that gain of
fset improvements are counteracted by loss mechanisms, (C) 1998 Americ
an Institute of Physics.