The nondestructive photoluminescence technology has been introduced to test and evaluate the growth of InGaAs/GaAs
Single-Quantum Well (SQW) by using Molecular Beam Epitaxy (MBE) technology. The experiments are carried out at
different temperature in order to test the effect of variation of gap energy. When temperature varied, the lineshape of
spectra changed, particular in the short wavelength part. The wavelength of emit light peak blue shift as well. We
indicate that the main mechanism of the radiative recombination at high temperature is of band-to-band origin. However,
at low temperature, exciton recombination is prevailing.
Laser diodes are efficient, compact, and inexpensive light sources and are already part of our modern life. However, their
use for spectroscopy has been limited due to the intrinsic problem of reliably controling output frequency and power. In
application where linewidth, stability or tunable narrow-band frequency output is required, free-running laser diodes are
from satisfactory. The problem can be overcome with External-Cavity Diode Lasers (ECDL). The obvious features of
my working are the optimization of the spatial mode and the design of the direction of light. We design the optical trace,
and having a well result. In the process of the experiment using grating for the modulation of external-cavity and
geometry optimization for maintaining the fixed direction of output beam. So when declining the grating for tuning the
frequency of laser, you have not the demand of changing the rest part in experiment. In the system, I utilized a feedback
to obtain a good precision of the controlling of the temperature and current.