OPT8241-CDK-EVM: the opt8241 depth data distribution like circle?

Part Number: OPT8241-CDK-EVM

Dear Larry&Anand,

        I have used  a different color represent depth data. just like the below figure.

        It's very interesting the depth distribution like circle. this phenomenon affected the RGB-D rectification

        Can you give me advise about this. 

        thanks&regards