11. This is compared to a reference beam , and an image of the tissue surface and subsurface is constructed. 12. The recording medium should be able to resolve fully all the fringes arising from interference between object and reference beam . 13. In a reflection hologram, the object and reference beams are incident on the plate from opposite sides of the plate. 14. Any change in the shape, orientation or wavelength of the reference beam gives rise to aberrations in the reconstructed image. 15. In this orientation, the test and reference beams each experience two front-surface reflections, resulting in the same number of phase inversions. 16. The complexity of such setups shifts from the optical setup to image post-processing, which involves the use of simulated reference beams . 17. Each point source wave interferes with the reference beam , giving rise to its own sinusoidal zone plate in the recording medium. 18. Some double-beam instruments have two detectors ( photodiodes ), and the sample and reference beam are measured at the same time. 19. In addition, part of the laser must shine directly onto a specific area of the display to act as a reference beam . 20. A common path interferometer is a class of interferometer in which the reference beam and sample beam travel along the same path.
