The high quality unintentionally doped Ga

0.4

In

0.6

As

0.85

P

0.15

quaternary semiconductor alloy

InPepilayers and distributed Bragg reflectors formed with Ga

0.4

In

0.6

As

0.85

P

0.15

/InPalternative layers have been grown on the S-doped high quality(100) InPsubstrates in an atmospheric or low pressure metal organic chemical vapor deposition system made up in our laboratory. The source materials are trimethylindium (TMIn)

trimethylgallium(TMGa)

arsine(AsH

3

) and phosphine(PH

3

). The growth temperature is 620℃ in the study. The pressure is 9.3×10

3

Pa in the reactor room. The lattice constant and composition parameters(x

y) were determined using double crystal X-ray diffraction and photoluminescence(PL) measurements. The lattice mismatch of the quaternary layers with the substrate was estimated to be less than 0.6%. The refractive index of Ga

0.4

-In

0.6

As

0.85

P

0.15

and InPsemiconductor were measured. The distributed Bragg reflectors are formed by laying down alternating layers of Ga

0.4

In

0.6

As

0.85

P

0.15

and InP with difference in refractive index. The function of the reflectivity of the DBR with different period number varied with wavelength and the period number of the DBR. According to the principle of the light through multiple-layer reflective films

the reflectivity of the DBR rapidly increased with the increasing of period number of DBR

when the center wavelength is 1.55 μm. The reflectivity of the DBR is greater than

99.97

%

as the period number of the DBR is 23. The experimental results have shown that we have successfully obtained the distributed Bragg reflectors

their period number are 3

4

7

11

15

19 and 23

respectively. It is well-known that the existence of the immiscible region in the Ga

x

In

1-x

-As

1-y

P

y

/InP. The composition(x

y) of the Ga

x

In

1-x

As

1-y

P

y

quaternary alloy is 0.4 and 0.15. They are in the region of immiscibility. It was found that the surface of the samples are grown in the region of immiscibility are rough rather than smooth. The interface quality between the Ga

x

In

1-x

As

1-y

P

y

and InPwas effected. But the reflectivity of DBR with period number 23 is only 54.44%

much lower than the theoretical results.