CowExtinction

Finite modulator extinction: light in the slot the protocol calls empty

6/6 passed in 1ms

Test	What it does	Result
test_error_caps	cow_data's error rate saturates at 1/2 as the extinction ratio falls to 0.001 dB and never passes it.	✅ pass
test_extinction_default	An undescribed modulator has residual 0.0, cow_data returns its inputs bit for bit, and the link rate equals the closed form.	✅ pass
test_extinction_guards	cow_residual, cow_monitor and q.IntensityKeying refuse a non-positive extinction ratio, and cow_data a signal error rate past 1/2.	✅ pass
test_extinction_link	Through q.Link a 20 dB modulator raises qber and gain, lowers the rate under the ceiling, and reports extinction, residual, monitored and certified rows a perfect one omits.	✅ pass
test_monitor_coverage	Coverage is 1 at 60 dB, 0.9919 at 20 dB and rises with monitoring, while the fringe stays the optic's contrast and the certified value is contrast times coverage.	✅ pass
test_no_cancellation	Over 40 to 15 dB extinction the data-line gain rises while the rate falls, and at 20 dB the rate is 54% of perfect on a gain 0.83% higher.	✅ pass