Change the schema of model.

An example is given below:

var data = {
  title:        'event 1',
  description:  'the first event',
  startDate:    '2014-01-02',
  endDate:      '2014-01-05',
  deadline:     '2014-01-01',
  duration:     '2',
  participants: [
    {
      name: 'John',
      facebookId: '234236367634',
      slot: [
        {
          startDate: '2014-01-03',
          startTime: '4',
          duration: '2'
        },
        ...
      ]
    },
    ...
  ]
};

Then post it with AJAX:

$.post('/newevent', data);