Create aJSON file

Hi Guys,

How do I create a JSON with the below structure pls:

{
  "field 1": "123",
  "field 2": "1.1.1",
  "field 3": "4.428",
   "Lines": [
    [ 0.00523, 0.00952, 0.01626 ],
    [ -0.00303, -0.00286, 0.00387 ],
    [ 0.00110, 0.00814, 0.00800 ],
    [ -0.00991, 0.00952, 0.00800 ]
  ]
}

thanks