AngularJS- How to pass data from one controller to another on ng-click()?

So I am trying to share data between two controllers on an on-click event. My code is as follows:

Controller

function userTypeController($scope, $location, CategoryService) {
  let vm=this;

vm.getCat=function(){

    CategoryService.getCategories() .then(function (response) 
        {
          $scope.categories=response.data.data.categories;
          $scope.index = 0;
          $scope.array = [];
          for(var i=0; i<$scope.categories.length/2;i++)
          $scope.array.push(i);


                                       });
    $location.path('/category');
};
  };

Say in my html for that controller, I have a button that calls the getCat function.

 <md-button md-whiteframe="8"  ng-click="utCtrl.getCat()">Submit<md-button>

In my category service , I have a function that returns a list of categories.

Service

return {
            getCategories: function () {
                return $http.get(url2);
            }

Now i want the array of categories that I get from the server to be accessible in my Categories controller. I was using $rootScope before to share the date from usertype controller to the other one but its not the ideal thing to do. I want $scope.array to be accessible in my categories controller so i can display that in its view. What would be the best way to do this. Thanks a lot!