[examples] fix eme bend example

meanas/test/test_examples_smoke.py

@@ -1,5 +1,6 @@
 from pathlib import Path
 import os
+import re
 import subprocess
 import sys
 
@@ -46,6 +47,10 @@ def test_eme_bend_example_smoke_runs(tmp_path: Path) -> None:
     assert 'straight effective indices:' in result.stdout
     assert 'cascaded bend through power' in result.stdout
 
+    straight_index_match = re.search(r'straight effective indices:\s*([0-9.]+)', result.stdout)
+    assert straight_index_match is not None, result.stdout
+    assert float(straight_index_match.group(1)) > 1.6
+
 
 def test_eme_taper_cmt_example_smoke_runs(tmp_path: Path) -> None:
     result = _run_example('eme_taper_cmt.py', tmp_path)