Optical flat

{
  "id": "MLC-T-IND-004025",
  "term": "Optical flat",
  "field": "Industrial and trades",
  "definition": "A precision-ground and polished piece of glass or fused silica with extremely flat surfaces, used as a reference standard for measuring the flatness of other optical components or surfaces. When placed in contact with another surface, interference fringes are formed, revealing deviations from flatness. These flats are typically specified to within a fraction of a wavelength of light.",
  "subject": "Optics and imaging",
  "translations": {
    "de": "optische Planplatte",
    "es": "plano óptico",
    "fr": "plan optique"
  },
  "url": "https://mlchart.com/terminology/industrial/optical-flat/"
}