Remove backslash from JSON output when forward slash in value

Question

I am getting value from data base with forward slash as "1-TIER/DIRECT".

I am using apex_json.write to write a JSON. But when I am doing that instead of "1-TIER/DIRECT" I am getting "1-TIER/DIRECT". Means getting backward slash "" in final output.

Want to return same value "1-TIER/DIRECT" as it is without "" backward slash.