The Quartet – Multi Purpose Receiver

The Quartet uses Sound & Bright’s patented Multi-Channel Random Quadrature (MCRQ) detection technology, designed for remote detection of sub-nanometre displacements across a wide range of acoustic and ultrasonic applications. It is suitable for use from laboratory research through to factory-floor inspection.

Robust & Versatile

Does not require high-accuracy optical components or precise positioning, making it exceptionally rugged. Compatible with a range of internal laser wavelengths from visible to infrared.

Fiberised Optical Head

A compact and versatile fiberised optical head mounts easily to suit a wide variety of measurement conditions and stand-off distances. The front lens can be changed or replaced as required.

Measurement Precision

Produces an analogue signal proportional to surface displacement. Output is calibrated at 100 mV per nanometre of displacement.

High Sensitivity on All Surface Types

By detecting and processing many speckle interference signals simultaneously, the Quartet achieves a stable demodulated output even with highly speckled beams — on rough, porous, rusted, or mirror-like surfaces.

Rapid Inspection

Streamlined electronic processing enables single-shot measurements on fast-moving objects at speeds up to metres per second.

Signal Indicators

Integrated visual and audible signal indicators assist setup optimisation. Internal calibration signal provides a calibrated output of 100 mV per nanometre of displacement.

• Patented MCRQ detection technology

  Sub-nanometre displacement sensitivity

  Fiberised optical head — interchangeable front lens

  Broad wavelength compatibility (VIS–IR)

  High sensitivity across all surface types including rough, porous, and mirror-like

  Calibrated output: 100 mV per nm displacement

  Single-shot measurement on fast-moving objects

  Visual and audible signal indicators

  Applications: research & education, sensing, defence & aerospace, industrial inspection

• Laser-Ultrasound NDT — General Purpose
  • The Quartet’s broad wavelength compatibility, fiberised optical head, and MCRQ sensitivity make it the go-to receiver for a wide range of laser-ultrasound NDT applications — from weld inspection and corrosion mapping to delamination detection in composites. Works on rough, porous, rusted, and mirror-like surfaces without adjustment.
• Aerospace & Defence Composite Inspection
  • Non-contact inspection of CFRP and GFRP structural components, bonded joints, and honeycomb sandwich panels. Combines with pulsed laser excitation sources for fully non-contact, couplant-free C-scan systems suitable for complex geometries.
• In-Process & Production-Line Inspection
  • Single-shot measurement capability at speeds up to metres per second enables integration into manufacturing lines for real-time quality control — on fast-moving or hot components where contact methods are impractical.
• Acoustic & Ultrasonic Research
  • Versatile receiver for laboratory acoustic and ultrasonic research — Lamb wave studies, surface acoustic wave measurements, guided wave propagation, and material property characterisation. Supports VIS–IR laser sources and is compatible with a wide range of excitation configurations.
• Structural Health Monitoring
  • Remote, non-contact monitoring of bonded structures, welds, and safety-critical components in aerospace, energy, and civil infrastructure. The Quartet’s ruggedness and broad surface compatibility suit demanding field environments.
• Automotive & Industrial Manufacturing
  • Inspection of welds, castings, forgings, and adhesive bonds in automotive and heavy manufacturing. High-speed scanning capability and tolerance for industrial surface conditions make it well-suited to production environments.