noun

• The distance of the path that in a vacuum would contain the same number of wavelengths as the actual path taken by a ray of light traveling through a medium.

  ‘For the interferometry to work, the optical paths have to be stable to fractions of a wavelength.’

  More example sentences

  • ‘Two tandem cells with a total optical path length of 1 cm were used for measuring the difference spectra.’
  • ‘The compact nature of the photoreceptor mass requires the pigment screen to be extremely dense, as very short optical paths separate receptors from each other.’
  • ‘The optical path difference is directly proportional to the cosine of the angle of refraction through the coating.’
  • ‘The difference in optical path length is proportional to the difference in indices of refraction.’