Acousto-Optics, Optical Computing, and Signal Processing - Applied Optics Fundamentals and Device Applications - page 139

3

1.888 eV
(656.6 nm)

2

1.686 eV
(735.2 nm)

1

1.487 eV
(833.6 nm)

1.503 eV
(824.8 nm)

5X

880 840 800 760 720 680 640 600

(nm)

FIGURE 3.28
Photoluminescence scan of MQWO device at room temperature.

corresponding photon energies are indicated in the figure. Most notable are
the obviously well-defined exciton emissions, which would not be observ-
able at room temperature without the QW structures. Peak 1 indicates the
exciton from the equal width QW structure, denoted period B in figure.
Peak 2 shows the emission from the unequal, period A wells. Peak 3 indi-
cates emission from the wide band gap AlGaAs p-type cap layer (layer 8 in
Figure 3.27). The energy of emission corresponds to an aluminum concentra-
tion of approximately 32%. Figure 3.29 shows another photoluminescence

2

1

1.763 eV
(703.2 nm)

1.579 eV
(785.2 nm)

3

1.961 eV
(632.1 nm)

1.563 eV
(793.2 nm)

2 X

880 840 800 760

720 680 640

600

(nm)

FIGURE 3.29
Photoluminescence scan of MQWO device at 12 K.