The Quartet is a laser ultrasound instrument based on our patented MCRQ (Multi-Channel Random Quadrature) technology. Developed with support from the National Science Foundation and NASA, the Quartet was designed to be compact, robust, and highly sensitive, even on rough surfaces—overcoming traditional limitations of optical interferometry.

FEATURES

Robust & Versatile
Because the technology does not require control over the length of the optical path within the system, the Quartet is not subject to stability issues common to most long cavity and path-stabilized interferometers. It does not require high accuracy optical components or positioning, making it exceptionally rugged.

Fiberized Optical Head
A relatively small and versatile fiberized optical head is easily mounted to fit a variety of measurement conditions and can be set-up for a wide-range of stand-off distances. Its front lens can be easily changed or replaced if necessary.

Measurement Precision
The Quartet produces an analog signal that is proportional to surface displacement.

High Sensitivity on all Surface Types and Materials
Thanks to its multiple detectors and high transmission optics, the Quartet accomplishes efficient light collection and thus, high sensitivity. This continues to be true when the system is fitted with a moderately powerful laser thanks to low noise detectors and electronics. By detecting and processing many speckle interference signals, the Quartet achieves a stable demodulated signal even when processing a highly speckled beam. This means that it can perform measurements on any kind of surface, including rough, porous, rusted or mirror-like surfaces.

Inspection on Rapidly Moving Objects
Streamlined electronic processing allows the Quartet to perform single shot measurements on fast-moving objects, at speeds up to meters per second.

Not Wavelength Dependent
The Quartet can be fitted with a range of internal laser wavelengths ranging from visible to infrared.

Signal Indicators
Incorporated within the system are visual and audible signal indicators designed to help the user optimize their measurement setup. The Quartet also includes an internal calibration signal allowing for a calibrated output at 100mV per nanometer of displacement.

Beam Chopper (Optional Upgrade)
The beam chopper is an optional feature which allows the system to be used on materials with poor heat conductivity, such as plastics or carbon fiber materials without damaging the surface. A perforated disk synchronized with the generation laser “chops” the beam at a regular interval in order to prevent the sample from being exposed to continuous laser power. This feature does not affect the quality of the signal as it allows the laser to be used at full power, in contrast to alternative solutions such as using continuous but low laser power systems. Once installed, the chopper can be turned on and off to suit the application. This upgrade is compatible with new generation Quartets and is easily installed by replacing the top cover of the system.