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Weak Light Lost Its Phase Lock
An SU(1,1) interferometer estimates displacement magnitude from total intensity without a local oscillator, phase locking or quadrature tracking.
Summary
An SU(1,1) interferometer estimates displacement magnitude from total intensity without a local oscillator, phase locking or quadrature tracking.
Conventional weak-signal measurements often need the signal phase in advance and coherent homodyne detection. The proposed method instead estimates magnitude independently of phase. Under ideal lossless conditions, the authors show total-intensity detection reaches the quantum Cramér–Rao bound, then analyze performance under optical loss. They report comparable performance across experimentally relevant regimes. This is a theoretical sensing framework and loss analysis, not a fielded detector.
Why it matters
An SU(1,1) interferometer estimates displacement magnitude from total intensity without a local oscillator, phase locking or quadrature tracking.
Limits and context
- This is a theoretical sensing framework and loss analysis, not a fielded detector.
Key claims
An SU(1,1) interferometer estimates displacement magnitude from total intensity without a local oscillator, phase locking or quadrature tracking.
Qualification: This is a theoretical sensing framework and loss analysis, not a fielded detector.
Evidence: source-2026-09-07-012
Sources
- arXiv preprint 2609.04363arXiv · primary research
Corrections
No corrections have been recorded for this story.