Compressively and tensile strained InGaAsP-InP MQW Fabry-Perot and Dis
tributed Feedback lasers emitting at 1.3-mum wavelength are reported.
For both signs of the strain, improved device performance over bulk In
GaAsP and lattice-matched InGaAsP-InP MQW lasers was observed. Tensile
strained MQW lasers show TM polarized emission, and with one facet hi
gh reflectivity (HR) coated the threshold currents are 6.4 and 12 mA a
t 20 and 60-degrees-C, respectively. At 100-degrees-C, over 20-mW outp
ut power is obtained from 250-mum-cavity length lasers, and HR-coated
lasers show minimum thresholds as low as 6.8 mA. Compressively straine
d InGaAsP-InP MQW lasers show improved differential efficiencies, CW t
hreshold currents as low as 1.3 and 2.5 mA for HR-coated single- and m
ultiple quantum well active layers, respectively, and record CW output
powers as high as 380 mW for HR-AR coated devices. For both signs of
the strain, strain-compensation applied by oppositely strained barrier
and separate confinement layers, results in higher intensity, narrowe
r-linewidth photoluminescence emissions, and reduced threshold current
s. Furthermore, the strain compensation is shown to be effective for i
mproving the reliability of strained MQW structures with the quantum w
ells grown near the critical thickness. Linewidth enhancement factors
as low as 2 at the lasing wavelength were measured for both types of s
train. Distributed feedback lasers employing either compressively or t
ensile strained InGaAsP-InP MQW active layers both emit single-mode ou
tput powers of over 80 mW and show narrow linewidths of 500 kHz.