Pass a controller to $ionicModal

Just add the controller you want to use in the body of the html of the modal. I created a fiddle to show you an example based off the one provided in the ionic docs: http://jsfiddle.net/g6pdkfL8/

But basically:

<-- template for the modal window -->
<ion-modal-view>
<ion-content ng-controller="ModalController">
 ...
</ion-content>
<ion-modal-view>