US 12449536 B1Patent grantUnited States

Remote Micro-Movement LiDAR Sensor

Official patent title

Ultraprecision frequency-domain light detection and ranging (LiDAR) system for remote micro-movement sensing

Arabic title: نظام فائق الدقة للكشف الضوئي وتحديد المدى (LiDAR) في مجال التردد لاستشعار الحركات الدقيقة عن بُعد

Invention

Problem

Conventional LiDAR systems are optimized for range and mapping rather than very small remote displacements. Micro-vibration sensing also becomes difficult where physical sensor contact is unsafe or impractical.

Why it matters

Remote micro-movement detection could support structural health monitoring, machine diagnostics, geohazard observation, and noncontact biological or industrial measurements.

Approach

The system combines RF intensity-modulated light, a Michelson interferometer with a fiber delay reference, an amplified free-space target arm, photodetection, and optoelectronic feedback that maps target movement to an RF frequency shift.

Who may benefit

Potential beneficiaries include precision-instrument manufacturers, structural-monitoring firms, machine-diagnostics providers, geoscience laboratories, defense sensing programs, and optical metrology researchers.

Potential value

The architecture senses movement in the frequency domain, where optoelectronic feedback can turn a small path-length change into a measurable frequency change using selectable spectrum, phase, or PLL analysis.

Background

LiDAR commonly measures distance or velocity from pulsed or continuous-wave light, but mapping-oriented systems may not resolve subtle target vibrations. Contact sensors can provide precision yet are unsuitable on hot, moving, inaccessible, or hazardous targets. Optoelectronic oscillators offer stable radio-frequency signals whose frequency responds to changes in optical delay. The disclosure integrates that principle with a Michelson-style free-space ranging path, using a fixed fiber delay as a reference and a reflected target path as the movement-sensitive arm.

Technology overview

A bandpass-filtered RF signal intensity-modulates a laser diode. A 50/50 coupler sends light through a silver-ended fiber delay and through a second arm containing a semiconductor optical amplifier, collimator, free-space region, and reflective target. Returned signals recombine at a photodetector. The converted electrical signal closes a feedback loop to the laser modulation path. A spectrum analyzer, phase detector, or phase-locked loop identifies frequency shifts attributed to target micro-movement. Claims cover the system, method, and processor instructions.

Potential applications

Structural vibration monitoring.
Remote machine-condition diagnostics.
Geohazard and infrastructure observation.
Noncontact displacement metrology.
Research on biological micro-movement sensing.

Evidence-supported advantages

Provides remote noncontact sensing.
Uses a fiber-delay reference and free-space target arm.
Amplifies the target path to compensate optical loss.
Offers several frequency-domain analysis options.
Integrates sensing with an optoelectronic feedback oscillator.

Development stage

An optical architecture, feedback loop, sensing method, and analysis alternatives are described; measured prototype displacement resolution, range, bandwidth, drift, and field performance were not established. The development stage was not independently verified.

Commercial opportunity

The design may interest optical metrology and condition-monitoring vendors. Productization requires a calibrated prototype, displacement sensitivity and bandwidth, range and reflectivity limits, phase-noise and drift data, vibration-reference comparisons, eye-safety analysis, atmospheric robustness, alignment tolerance, component-cost reduction, and field tests on the intended structures or machines.

Patent classifications

WIPO IPC

G01S17/26Radio direction-finding and navigation; determining distance or velocity by radio waves; locating or detecting presence by reflected or reradiated waves; analogous arrangements using other waves
G01S17/88Radio direction-finding and navigation; determining distance or velocity by radio waves; locating or detecting presence by reflected or reradiated waves; analogous arrangements using other waves

CPC

G01S17/58Radio direction-finding and navigation; determining distance or velocity by radio waves; locating or detecting presence by reflected or reradiated waves; analogous arrangements using other waves
G01S7/4865Radio direction-finding and navigation; determining distance or velocity by radio waves; locating or detecting presence by reflected or reradiated waves; analogous arrangements using other waves
G01S17/88Radio direction-finding and navigation; determining distance or velocity by radio waves; locating or detecting presence by reflected or reradiated waves; analogous arrangements using other waves
G01S17/26Radio direction-finding and navigation; determining distance or velocity by radio waves; locating or detecting presence by reflected or reradiated waves; analogous arrangements using other waves
G01S7/4818Radio direction-finding and navigation; determining distance or velocity by radio waves; locating or detecting presence by reflected or reradiated waves; analogous arrangements using other waves
G01S17/34Radio direction-finding and navigation; determining distance or velocity by radio waves; locating or detecting presence by reflected or reradiated waves; analogous arrangements using other waves
G01S7/484Radio direction-finding and navigation; determining distance or velocity by radio waves; locating or detecting presence by reflected or reradiated waves; analogous arrangements using other waves

Inventors

First inventorMohamed Yehia Mohamed Shalaby

Keywords

LiDAR
micro-movement
frequency domain
Michelson interferometer
optoelectronic oscillator
fiber delay
vibration sensing
remote metrology

Patent document and drawings

The patent publication is mapped to this record. Patent drawings remain within that publication; no separately cleared public media package has been supplied.