ionic side menu logo in header

Use below code in main template html file.

<ion-side-menus expose-aside-when="large" enable-menu-with-back-views="true">
        <ion-pane ion-side-menu-content>
        </ion-pane>
      <ion-side-menu side="left">
            <header class="bar bar-header bar-positive">
                <div>
                      <img class="margin-top:4px; float:left" src="images/logo.png"/>
                </div>
            </header>
            <ion-content class="has-header">
           </ion-content>
        </ion-side-menu>
</ion-side-menus>

and don't forget to write attribute "has-header" in your child templates files like:

<ion-view class="bubble-background" hide-back-button="true">
    <ion-nav-buttons side="left">
        <button menu-toggle="left" class="button button-icon icon " ></button>
      </ion-nav-buttons>
    <ion-content class="has-header has-footer">
     </ion-content>
</ion-view>