---
res:
  bibo_abstract:
  - Freeform optics belong to the increasingly important elements in optical research
    and industry, which pose several challenges regarding design and highly precise
    manufacturing. First being used in cameras and for focusing, nowadays freeform
    optics are used in a broad range of applications, from lighting to LiDAR, from
    endoscopy to photovoltaics, and from astronomical instruments to quantum cryptography.
    Designing freeform optics can be based on different theories and methods. Fabrication
    is possible by mechanical methods, such as diamond turning or high-precision milling,
    often followed by different polishing techniques, as well as laser-based techniques,
    mainly applying different lithographic techniques. Here, we give an overview of
    recent design and optimization methods, production methods used during the last
    years, and applications of freeform optics, including the possibility to combine
    freeform optics with tunability for different applications. We describe the opportunities
    of new applications as well as common problems and give an outlook towards future
    directions of research and development.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Tomasz
      foaf_name: Blachowicz, Tomasz
      foaf_surname: Blachowicz
  - foaf_Person:
      foaf_givenName: Guido
      foaf_name: Ehrmann, Guido
      foaf_surname: Ehrmann
  - foaf_Person:
      foaf_givenName: Johannes
      foaf_name: Fiedler, Johannes
      foaf_surname: Fiedler
  - foaf_Person:
      foaf_givenName: Reinhard
      foaf_name: Kaschuba, Reinhard
      foaf_surname: Kaschuba
  - foaf_Person:
      foaf_givenName: Andrea
      foaf_name: Ehrmann, Andrea
      foaf_surname: Ehrmann
      foaf_workInfoHomepage: http://www.librecat.org/personId=223776
    orcid: 0000-0003-0695-3905
    orcid_put_code_url: https://api.orcid.org/v2.0/0000-0003-0695-3905/work/214321986
  bibo_doi: 10.3390/micro6020035
  bibo_issue: '2'
  bibo_volume: 6
  dct_date: 2026^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/2673-8023
  dct_language: eng
  dct_publisher: MDPI AG@
  dct_subject:
  - photopolymerization
  - tunable micro-optical freeform elements
  - two-photon polymerization
  - multiphoton lithography
  - direct laser writing
  - diamond turning
  dct_title: Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities
    and Challenges@
...