The reflectivity characteristics of Distributed Bragg Reflector (DBR) are described by an equivalent F-P cavity method.The DBR structure is grown by MOCVD.The GaAs buffer layer is grown on the n-type GaAs substrate

its thickness is 500 nm.The DBRs is consisted of Al

0.12

Ga

0.88

As/Al

0.9

Ga

0.1

As and the optical thickness of each layer is of quarter wavelength.The top DBR is consisted of 22 pairs

and the bottom DBR is consisted of 34 pairs.The active region is consisted of three undoped multiple quantum wells structure of GaAs/Al

0.3

Ga

0.7

As.The p-type dopant is carbon and the n-type dopant is silicon. The reflectivity of DBR with asymmetric structure is calculated and discussed.The structure of 850 nm center wavelength of the DBR reflectance spectrum was designed.The thickness of DBR structure was determined by its reflectivity and center wavelength. The experimental results indicated that this is an effective method for the optimal design of DBR.As a result in practice

it is easy to output laser when the periodicity of reflector in bottom DBR structure is about 30 pairs and periodicity of reflector in top DBR structure is about 20 pairs. Be compared with the experimental results

it is found that the simulative results are similar with the experimental results.It indicates that the simulative results are reliable and it can also be used for simulating some others.The experiences indicated that the simulation is an important guideline for developing and fabricating the DBR.