wrong query with slashes

gistfile1.txt

{
  "responseHeader":{
    "status":400,
    "QTime":5,
    "params":{
      "facet.field":"fgs_label",
      "json.nl":"map",
      "indent":"on",
      "start":"0",
      "fq":["-RELS_EXT_isConstituentOf_uri_mt:[* TO *]",
        "RELS_EXT_isViewableByUser_literal_ms:\"admin\" OR RELS_EXT_isViewableByRole_literal_ms:\"authenticated user\" OR RELS_EXT_isViewableByRole_literal_ms:\"administrator\" OR ((*:* -RELS_EXT_isViewableByUser_literal_ms:[* TO *]) AND (*:* -RELS_EXT_isViewableByRole_literal_ms:[* TO *]))"],
      "rows":"20",
      "version":"1.2",
      "facet.limit":"20",
      "q":"fgs_label_s:(/large//image)",
      "facet.mincount":"2",
      "facet":"true",
      "wt":"json",
      "debugQuery":"true"}},
  "error":{
    "msg":"org.apache.solr.search.SyntaxError: Cannot parse 'fgs_label_s:(/large//image)': Lexical error at line 1, column 28.  Encountered: <EOF> after : \"/image)\"",
    "code":400}}