Merge associative rows of two 2d arrays related by a shared column values

I have to multidimensional arrays like this:

array 
(
  [0] => Array
      (
        [field1] => A
        [field2] => 100
        [field3] => 20
      )

  [1] => Array
      (
        [field1] => B
        [field2] => 100
        [field3] => 30
      )
  [2] => Array
      (
        [field1] => C
        [field2] => 100
        [field3] => 30
      )
)



 array 
(
  [0] => Array
      (
        [field1b] => A
        [field2b] => 500
        [field3b] => 0
      )

  [1] => Array
      (
        [field1b] => B
        [field2b] => 300
        [field3b] => 10
      )
)

I want to merge both arrays using field1 as Key, and having in mind that arrays aren't same size.

The result array should be:

array 
(
  [0] => Array
      (
        [field1] => A
        [field2] => 100
        [field3] => 20
        [field2b] => 500
        [field3b] => 0

      )

  [1] => Array
      (
        [field1] => B
        [field2] => 100
        [field3] => 30
        [field2b] => 300
        [field3b] => 10
      )
  [2] => Array
      (
        [field1] => C
        [field2] => 100
        [field3] => 30
      )
)

<?php
$array1 =  array 
(
  "0" => Array
      (
        "field1" => "A",
        "field2" => "100",
        "field3" => "20"
      ),

  "1" => Array
      (
        "field1" => "B",
        "field2" => "100",
        "field3" => "30"
      ),
  "2" => Array
      (
        "field1" => "C",
        "field2" => "100",
        "field3" => "30"
      )
);

$array2 =  array 
(
  "0" => Array
      (
        "field1b" => "A",
        "field2b" => "500",
        "field3b" => "0"
      ),

  "1" => Array
      (
        "field1b" => "B",
        "field2b" => "300",
        "field3b" => "10"
      )
);

$new_array1 = [];
foreach ($array1 as $object1) {
  $new_array1[$object1['field1']] =  $object1;
}

$new_array2 = [];
foreach ($array2 as $key => $object2) {
  $new_array2[$object2['field1b']] =  $object2;
}
$new_array = [];
foreach($new_array1 as $key => $val)
{
    $new_array[$key]['field1'] = $val['field1'];
    $new_array[$key]['field2'] = $val['field2'];
    $new_array[$key]['field3'] = $val['field3'];
    if (array_key_exists($key,$new_array2))//Check if the key is exists in an array
    {
      $new_array[$key]['field2b'] = $new_array2[$key]['field2b'];
      $new_array[$key]['field3b'] = $new_array2[$key]['field3b'];
    }       
}

print_r($new_array);

DEMO

You can try it.