Plasma & Gas density measurement

SID4 V Vacuum


Phasics is innovating by proposing the first off-the-shelf vacuum compatible wavefront sensor on the market. The SID4 V is designed to perform wavefront measurements under high vacuum. the wavefront measurement is realized in-situ in the same condition as the experiment. Our new SID4 V vacuum wavefront sensor is also used to characterize laser beams after compression inside the compressor vessel. Finally, gas jet and plasma density are now measured as close to the target as possible.

BENEFITS: With Phasics’s unique strategy it’s now possible to correct the aberrations of every single optical element up to the target location inside the vacuum chamber.

Key Features


  • Vacuum compatibility > 10-6 mbar
  • High resolution 160 x 120 phase pixels
  • Spectral range from 400 nm to 1100 nm
  • Diverging beam compatible
  • Invariant to thermal and mechanical vacuum constraints
  • Tolerates vacuum-cycles without any performance decrease
  • Both functional under vacuum and atmospheric pressure
  • Low outgassing



Vacuum compatibility> 10-6 mbar
Wavelength range400 - 1100 nm
Aperture dimension4.73 x 3.55 mm2
maximum NA (optional software necessary)0.2
Spatial resolution29.6 µm
Phase & intensity sampling160 x 120
Accuracy15 nm RMS
Resolution (Phase)2 nm RMS
Acquisition rate60 fps
Real-time processing frequency7 Hz (full resolution)
InterfaceGiga Ethernet
MTBF> 10 years
Dimensions (w x h x l)54 x 46 x 75.3 mm
Weight~ 250 g

SID4 Density software


SID4 DENSITY software package supports the whole process to measure gas and plasma electron density. It calculates density maps from phase acquisition. It also offers various options for acquisition and data analysis.



ApplicationAny axisymmetric monoatomic gas jet/plasma for inverse-Abel transform analysis
Probe sourceWhite light (halogen), LED, laser or fs-laser
PressureFrom 2 to 300 bars
Plasma lengthDepends on the imaging system (typically 2 mm long and diameter of 0.2 mm)
AcquisitionReal Time, programmed, trigger
SettingsWavelength, magnification, jet direction, gas type
AnalysisDensity map & profiles, Symmetrization, filters

Performances such as the spatial resolution or the density resolution entirely depend on both the optical set-up (imaging system, probe source) and the injected gas (molar refractivity). Please contact us for an estimation of specifications for your set-up.
As an example, for an laser produced plasma using an Argon gas jet at working pressure between 2 and 300 bars, the lowest measured Argon density in a single shot is: 1017 particles/cm3 with a nozzle of 1.5 mm diameter.

Contact us to get those products