Skip to content
oanor
Sign up free
Marketplace Pricing Features Sign in
GET /v1/critical-angle

Critical angle (TIR)

Try it live

10 free calls per day — no sign-up, no API key. Goes through the oanor gateway.

Custom headers (optional)
api.oanor.com/snell-api

It works. Grab an API key and use it in your project.

Get an API key

Code snippets

curl "https://api.oanor.com/snell-api/v1/critical-angle" \
  -H "x-oanor-key: oanor_test_..."
await fetch("https://api.oanor.com/snell-api/v1/critical-angle", {
  headers: { "x-oanor-key": "oanor_test_..." }
});
$ch = curl_init("https://api.oanor.com/snell-api/v1/critical-angle");
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$out = curl_exec($ch);
import requests
requests.get(
    "https://api.oanor.com/snell-api/v1/critical-angle",
    headers={"x-oanor-key": "oanor_test_..."}
)

Example response

A real response from this endpoint, captured by the latest health check.

{
    "data": {
        "note": "At incidence angles beyond the critical angle, light is totally internally reflected (the basis of optical fibres).",
        "formula": "θc = asin(n2 / n1).",
        "index_1": 1.333,
        "index_2": 1.0003,
        "medium_1": "explicit",
        "medium_2": "air",
        "critical_angle_deg": 48.62613
    },
    "meta": {
        "timestamp": "2026-06-04T10:18:57.187Z",
        "request_id": "81b6b88c-aa88-48f4-8186-6978a8d34a0b"
    },
    "status": "ok",
    "message": "Critical angle (TIR)",
    "success": true
}