Process and device to minimise wavefront aberrations in polychromatic optical imaging

 

Offers apochromatic systems for wide-band optical signals that are inexpensive, diffraction-limited, and extremely mechanically and thermally stable. No need for filters while improving signal statistics. Only one optical imager is necessary for all wavelengths in the spectral range. System can be used in areas exposed to heat and radiation. Depending on application either crown or flint glass can be used.

"Definitionshelligkeit"

PETRA III beamline

 

Problem

Technical optical applications are still dominated by achromatic optical imaging systems with their extensive image aberrations. The chromatic aberrations make achromatic lenses unusable for all wide-band optical applications. Increasingly stringent requirements imposed on the polychromatic resolution, required spectral range and its usable bandwidth therefore preclude the use of achromatic lenses. In addition, Fraunhofer design air-spaced achromatic lenses are not sufficiently rugged to withstand unavoidable mechanical impacts, particularly in the case of large apertures.

Innovation

To meet the specified requirements it was necessary to develop new types of lenses. In this context it emerged that an innovative design methodology could produce systems that not only exhibit achromatic imaging properties and have the desired thermal and mechanical ruggedness but also reduce the demands on fabrication technology and quality assurance, resulting therefore in a production technology that is much less expensive.

Fields of Application

Diffraction-limited optical imaging devices with large apertures (from 50 mm to 200 mm) and high luminosity (from K’=4) for optical relays, measuring lenses, camera lenses, collimators etc. with large usable spectral range e.g.:

  • Visible, VIS, 400 - 700 nm
  • Near infra-red, NIR, 750 - 1000 nm
  • Near ultra-violet, NUV, 250 - 350 nm

Advantages

Initial tests and successful trials have been taking place in the form of astronomical applications (VIS) with a system of aperture-focal length 100-1000 mm since 2005, by synchrotron light (VIS) source PETRA III for optical beam guidance (100-700, 150-2250) for bunch length measurement since 2008, and with transition radiation (NIR) on a 50-540 mm lens in an ODR (optical distribution rack) set-up for FLASH in 2011.