Time-Reversed Wave Cavity

Phase-conjugate resonator for time-reversed EM wave research

$265 plan

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Technical Specifications

Classification Scalar EM — Detection

Primary Mechanism Phase conjugation via 4-wave mixing

Optical Version BaTiO₃ crystal + 532nm pump laser

RF Version Varactor 4-wave mixer, 100 MHz–1 GHz

Detection Interferometric fringe visibility

Time-Reversal Fidelity >90% (optical version achievable)

Difficulty 4 / 5

Est. Build Cost $600–$1,400

Est. Build Time 6–10 weeks

Overview

Bearden's scalar EM theory assigns special importance to phase-conjugate (time-reversed) waves — EM waves whose phase is exactly reversed relative to a reference wave. When a time-forward wave and its time-reversed conjugate interfere, they form a longitudinal (scalar) standing wave. Phase conjugation is physically realized through 4-wave mixing in a nonlinear medium. This cavity design uses a BaTiO₃ (barium titanate) crystal as the phase-conjugate mirror, driven by a pulsed Nd:YAG or DPSS pump laser. The plan covers crystal characterization, pump geometry, signal/idler beam alignment, and measurement of the phase-conjugate return using an interferometer. An RF analog is also provided using varactor-based 4-wave mixing for those without laser access. The RF version operates at 100 MHz–1 GHz and is accessible at bench scale.

Intended Research Use

Phase conjugation, time-reversal symmetry experiments, 4-wave mixing characterization, Bearden T-E wave formation studies.

Bill of Materials (16 components)

#Component

01 BaTiO₃ crystal, optical grade (10×10×5 mm)

02 DPSS laser module, 532nm, 50mW

03 Beam splitter cube, 50:50, 532nm coating

04 Mirror mounts (precision, kinematic, ×4)

05 Photodetector (Si PIN, >1 GHz, ×2)

06 Optical table or breadboard (600×900mm)

07 Oscilloscope, 1 GHz bandwidth

08 Variable attenuator (optical density filters)

09 Spatial filter assembly (pinhole + objective)

10 Beam expander (5×)

11 RF 4-wave mixer PCB (varactor-based, plan includes)

12 Varactor diode (BB133 or SMV1235, ×4)

13 HF signal generator (100 MHz)

14 RF power meter

15 Laser safety goggles (OD4+ at 532nm)

16 Interferometer alignment laser (650nm, 1mW)

Get Build Plan

Complete plan PDF including all specs, winding geometry, drive circuit schematics, measurement protocols, and Gerber files where applicable.

$265 one-time

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Complete build documentation (PDF)

Winding specs + circuit schematics

Measurement + verification protocols

Sourcing guide for all BOM items

Lifetime access, no subscription

Build Difficulty

Advanced — precision fabrication + measurement equipment required.

Est. cost: $600–$1,400
Est. time: 6–10 weeks