"оптичних волокнах" meaning in Ukrainien

{
  "categories": [
    {
      "kind": "other",
      "name": "Formes de locutions nominales en ukrainien",
      "parents": [],
      "source": "w"
    },
    {
      "kind": "other",
      "name": "Ukrainien",
      "orig": "ukrainien",
      "parents": [],
      "source": "w"
    }
  ],
  "forms": [
    {
      "form": "опти́чних воло́кнах",
      "tags": [
        "canonical"
      ]
    }
  ],
  "lang": "Ukrainien",
  "lang_code": "uk",
  "pos": "noun",
  "pos_title": "Forme de locution nominale",
  "raw_tags": [
    "^((optytšnykh voloknakh))"
  ],
  "senses": [
    {
      "form_of": [
        {
          "word": "опти́чне волокно́"
        }
      ],
      "glosses": [
        "Locatif pluriel de опти́чне волокно́."
      ],
      "id": "fr-оптичних_волокнах-uk-noun-LSK0hAxg"
    }
  ],
  "tags": [
    "form-of",
    "inanimate",
    "neuter"
  ],
  "word": "оптичних волокнах"
}

{
  "categories": [
    "Formes de locutions nominales en ukrainien",
    "ukrainien"
  ],
  "forms": [
    {
      "form": "опти́чних воло́кнах",
      "tags": [
        "canonical"
      ]
    }
  ],
  "lang": "Ukrainien",
  "lang_code": "uk",
  "pos": "noun",
  "pos_title": "Forme de locution nominale",
  "raw_tags": [
    "^((optytšnykh voloknakh))"
  ],
  "senses": [
    {
      "form_of": [
        {
          "word": "опти́чне волокно́"
        }
      ],
      "glosses": [
        "Locatif pluriel de опти́чне волокно́."
      ]
    }
  ],
  "tags": [
    "form-of",
    "inanimate",
    "neuter"
  ],
  "word": "оптичних волокнах"
}