Lens testing

Introduction

COMPLETE TEST
Our solutions provide a complete lens quality control from a single wavefront acquisition:

  • MTF (modulation transfer function) for any frequency and azimuth, or through focus
  • TWE (transmitted wavefront error)
  • Aberrations (Zernike coefficients) – up to high order – with real-time filtering

 

UNIQUE CAPABILITIES
Our exclusive measurement principle enables:

  • Multiple wavelengths on the same set-up
  • Off axis wavefront analysis for rigorous MTF and TWE
  • Comparison to Zemax design in the measurement plane
  • Radiometric test
MTF measurement

 

transmitted wavefront error

For

FROM UV TO FAR INFRARED:

  • Fast & powerful lens quality control in production: Aberrations and MTF on the same bench
  •  

  • Transmitted wavefront error of subassembly, even strongly aberrated: avoid expensive rework

 

  • Quality control of lens in R&D: Accurate feedback to designers
  •  

  • Third-party lens benchmark for optics integrators: Complete and rigorous comparison

Achievements

OFF-AXIS WAVEFRONT & MTF


  • at multiple wavelengths
  • 0.5% MTF precision from -90° to + 90° FoV

 

distorsion+MTF+ Coma + Transmission

COMPARISON TO ZEMAX DESIGN


  • in the measurement plane

Comparison to Zemax design

INFRARED LENS MEASUREMENT


  • Very fast: < 1min per lens
  • One shot measurement
  • Up to 100 mm optics of high NA (up to f/1) at 10.6μm

REAL-TIME ZERNIKE


  • A user-chosen set of Zernike coefficients can be subtracted in live to help aligning

 
Zernike coefficient measurement

Introduction

Phasics offers an exclusive lens measurement principle thanks to its patented technology.  The wavefront is directly measured with no relay lens.  Calculations then uses light propagation theory to provide both wavefront aberrations and MTF. The MTF is obtained at any frequency without using a target.

Set Up

► EXCLUSIVE SET-UP WITH NO RELAY LENS
Phasics solution stands out for its direct set-up :

  • No relay lens
  • No reference arm
  • No null lens
  • Multiple wavelengths (use of filters or multiple sources) with the same wavefront sensor on the same set-up

This direct set-up simplifies alignment and it enables advanced result analysis, especially off-axis
 
Note: double pass set-up is possible

Advantages

DIRECT SET-UP
No relay optics – no reference arm – no null lens


  • Versatile : covers large ranges of optics with no set-up changes
  • Simplified alignment process
  • Reliable measurement in exit pupil on and off axis – no pupil clipping
  • Compact + Insensitive to vibrations for an easy integration in production line

BROADBAND TEST ON THE SAME BENCH


  • Interferometry at any wavelength such as lens working wavelengths
  • Chromatic aberration measurement

RELIABLE MEASUREMENT


  • The high resolution of phase and intensity maps ensures robust computation

Scientific publications

Proc. SPIE 9633, Optifab 2015, 96331U

DOI: 10.1117/12.2195805

Automated full-field range OPD and MTF measurement bench for automotive objective benchmark

Proc. SPIE 9633, Optifab 2015, 96331T

DOI: 10.1117/12.2195806

Recent developments in IR metrology using quadri wave lateral shearing interferometry

Optics.org

"New solutions for fast and accurate lens quality control" (press article)

Proc. SPIE 8884, Optifab 2013, 88841M

DOI: 10.1117/12.2031635

Optical test bench for high precision metrology and alignment of zoom sub-assembly components

SPIE Security & Defense Baltimore

DOI: 10.1117/12.919204

On-axis and off-axis characterization of MWIR and LWIR Imaging Systems using Quadri Wave Interferometry

SPIE Security & Defense Orlando

DOI: 10.1117/12.883967

Fast MTF and Aberrations Analysis of MWIR and LWIR Imaging Systems using Quadri Wave Interferometry

Laser Photonik March

"Optical systems characterization with high dynamic, resolution and precision" (press article)

This article is also available in German: Charakterisierung von optischen systemen mit hoher dynamik, auflösung und präzision

SPIE Security & Defense Cardiff

DOI: 10.1117/12.800325

Thermal Infrared Optical Metrology using quadri-wave latereal shearing interferometry