Find the conditions for better measurement.

0:00 · The architecture

This is a proposed compact optical bench for Peterson Quantum Sensing. Two Mach Zehnder interferometers share a middle beam splitter. Follow the light first, then the electronics. The animation explains phase control, noise stationary locking, and coded probe recovery. It illustrates mechanisms, rather than measured performance.

0:24 · Split and propagate

The first beam splitter sends coherent light into two arms. Each folding mirror redirects its arm toward the shared corner. The colors identify routes, not different wavelengths. The moving markers show direction. Real light travels straight between components, and much faster than this illustration.

0:45 · Phase modulation

The electro optic modulator sits between beam splitter one and mirror one. Its electric field changes the crystal refractive index, shifting optical phase. The crystal does not slide like a piston. A known electrical waveform supplies the phase code. Interference downstream converts that phase change into a measurable intensity response.

1:09 · Shared interference

At the shared beam splitter, each incoming arm contributes to both outgoing arms. Their fields add with phase sensitive interference. As the first stage phase changes, power moves between these two paths. Both paths feed the second stage. The old intermediate detector is therefore removed.

1:29 · Two final outputs

The second pair of arms acquires another relative phase before the final beam splitter. The two photodetectors convert output intensity into electrical current. In this ideal lossless model, their powers are complementary. Their sum tracks total power, while their difference contains phase dependent information.

1:50 · Fast fringe locks

A calibrated fast lock compares the readout with its target and drives a piezoelectric mirror actuator. A small mirror displacement changes optical path length. Negative feedback opposes phase drift within the loop bandwidth. The illustrated actuator motion is exaggerated. Residual noise remains, even after the phase is held near its target.

2:13 · Separate the signals

Small, distinct actuator tags can share the same detector signal. Synchronous demodulation compares that signal with each reference to separate the responses. The two stages are coupled, so calibration must show that both controls remain distinguishable at the chosen bias. More detector channels alone do not guarantee independent phase information.

2:38 · Measure the objective

Noise stationary locking examines a defined noise band and normalizes the measured noise by an appropriate power factor. Known probe and dither contributions must be excluded or accounted for. This example uses a synthetic technical noise objective. A lower score is useful only while the instrument retains enough power and sensing response.

3:02 · Probe the slope

The supervisor makes a small setpoint nudge and checks whether the noise score rises or falls. Repeated measurements estimate its slope. Near an interior minimum, opposite nudges balance. Zero slope alone is insufficient: a maximum also has zero slope. Curvature and operating constraints determine whether the point is useful.

3:24 · Two time scales

The supervisor slowly adjusts the fast lock setpoint toward a useful noise optimum. The inner loop keeps the optical phase near that moving target. It does not eliminate every disturbance or create squeezing. The illustrated improvement comes from the assumed technical noise landscape and must be tested on a real bench.

3:46 · Coded-probe readout

The known modulator waveform also provides a reference for correlation. The processor compares the detector response with that reference, allowing a coded probe component to be estimated alongside control signals. This layout uses internal arm modulation. Independent dark port field injection would require a separate coupling point.

4:09 · The complete system

The complete concept combines fast phase stabilization, slow supervision of a noise statistic, and a known probe for readout. The shared beam splitter reduces optics, while shared acquisition reduces duplicated electronics. The essential experimental question is whether this combination improves a useful measurement while preserving stable control and sensing sensitivity.