返回laravel模型时将json解析为数组

I have a laravel model Course and there is an attribute times has a JSON string (time table to be clear).

when I request the data in controller $courses = Course::all() I want to parse the times attribute automatically to array, this is because when I return $courses as JSON it will format the times to json and it is already JSON so it return non understandable string format, so I need times to json_decode or to parse to array.

Is there any way to do that in the model or in the controller ??

I can do that by foreach on the $courses and reformat the times , but I think there must be another simple solution ...