"photopair" meaning in English

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "photo",
        "3": "pair"
      },
      "expansion": "photo- + pair",
      "name": "prefix"
    }
  ],
  "etymology_text": "photo- + pair",
  "forms": [
    {
      "form": "photopairs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "photopair (plural photopairs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "English terms prefixed with photo-",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Physics",
          "orig": "en:Physics",
          "parents": [
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A pair of photons, produced simultaneously, typically moving in opposite directions"
      ],
      "id": "en-photopair-en-noun-4gADnBCx",
      "links": [
        [
          "physics",
          "physics"
        ],
        [
          "pair",
          "pair"
        ],
        [
          "photon",
          "photon"
        ]
      ],
      "raw_glosses": [
        "(physics) A pair of photons, produced simultaneously, typically moving in opposite directions"
      ],
      "topics": [
        "natural-sciences",
        "physical-sciences",
        "physics"
      ]
    }
  ],
  "word": "photopair"
}

{
  "etymology_templates": [
    {
      "args": {
        "1": "en",
        "2": "photo",
        "3": "pair"
      },
      "expansion": "photo- + pair",
      "name": "prefix"
    }
  ],
  "etymology_text": "photo- + pair",
  "forms": [
    {
      "form": "photopairs",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "photopair (plural photopairs)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English nouns",
        "English terms prefixed with photo-",
        "en:Physics"
      ],
      "glosses": [
        "A pair of photons, produced simultaneously, typically moving in opposite directions"
      ],
      "links": [
        [
          "physics",
          "physics"
        ],
        [
          "pair",
          "pair"
        ],
        [
          "photon",
          "photon"
        ]
      ],
      "raw_glosses": [
        "(physics) A pair of photons, produced simultaneously, typically moving in opposite directions"
      ],
      "topics": [
        "natural-sciences",
        "physical-sciences",
        "physics"
      ]
    }
  ],
  "word": "photopair"
}