Here is an example of a deep copy, for reference. Note that this is not efficient - you'd be better off using a module as GrandFather suggests. (Modules are great for getting things done, but don't always show you how they are doing them.)

my @a1; # First array

# Pretend we're putting something in the first array.

my @a2=aoacpy(@a1);

sub aoacpy
{
  my @array_in=@_;
  my @array_out;
  # Iterate through parent array.
  for (my $i=0; $i<scalar(@array_in); $i++)
  {
    # Iterate through child array - note that 
    # we do this for each member of the parent 
    # array.
    for (my $j=0; $j<scalar($array_in[$i]); $j++)
    {
      $array_out[$i][$j]=$array_in[$i][$j];
    }
  }
  return @array_out;
}
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I'm now scratching my head trying to work out why this is so slow - it shouldn't be iterating that many times.