__WEBPACK_IMPORTED_MODULE_7_laravel_echo__.Echo is not a constructor in Angular 5

I am implementing socket.io using laravel pusher in laravel and I have also installed laravel-echo and pusher-js using npm install --save laravel-echo pusher-js in frontend. But getting error when I am trying to execute following code ,

let echo = new Echo({
  broadcaster: 'pusher',
  key: PUSHER_API_KEY,
  cluster: PUSHER_CLUSTER
});

echo.channel('updateMainGrid')
  .listen('UpdateGridData', (e)=>{
    console.log(e);
  });

Please help me to salve this issue.