For conventional high power quantum well (QW) lasers whose p-n junction is located in or near the active region

the dark spot defects (DSDs) and the dark line defects (DLDs) develop and move to the active layer during aging process

which increases non-radiative recombination centers and causes device to degrade. As a result

the threshold current increases

while the output power and the differential coefficient decrease at the same time. However

for the RJ lasers

the p-n junction is separated from the active layer by the presence of a thin waveguide layer between the active layer and p-n junction. The mobile defects are absorbed in the p-n junction located outside the active layer because of the electric field of p-n junction. Thus

the non radiative recombination centers in the active layer decrease

the degradation of RJ lasers is decided by the degradation of p-n junction. Unless the p-n junction suffers serious damage

a much longer lifetime and a better reliability may be expected for RJ lasers. We designed and succeeded in fabricating 808 nm AlGaAs/GaAs separate confinement heterostructure(SCH)single quantum well RJ lasers with a cavity length of 900 μm and a stripe width of 100μm by depositing the material on GaAs substrate with metal organic chemical vapor deposited (MOCVD). Its epitaxial structure is different from the conventional 808 nm AlGaAs/GaAs SQW semiconductor lasers. The SCH active region consists of a 10 nm thick Al

0.07

Ga

0.93

As layer between two 0.1 μm thick p-Al

0.3

Ga

0.7

As waveguide layers. One p-Al

0.3

Ga

0.7

As layer separates the active layer from the p-n junction

and also carries out optical and carrier confinement together with another p-Al

0.3

Ga

0.7

As layer. The n and p cladding layers are each 1.3 μm thick. Compared to the conventional 808 nm GaAs/AlGaAs high power SQW laser structure

there is a 0.1 μm thick p AlGaAs layer between the p-n junction and active region

as shown in Table 1. To decrease the effect of dislocations in substrate on the epitaxial layer quality

a n

+

-GaAs buffer layer is grown between the substrates and n-Al

0.5

Ga

0.5

As lower cladding layer. The DC characteristic of RJ lasers was measured. Compared with the conventional AlGaAs/GaAs high power semiconductor laser

the remote junction (RJ) high power semiconductor laser shows that the threshold current (

I

th

) and the threshold voltage (

V

th

) are large. During 3000 hour constant current LD mode aging process

the RJH lasers showed a reduction of threshold current and a fluctuate increase of output power.