Abstract A method is described for making holograms by means of linearly polarized object and reference beams, the reference beam being reflected inside the photosensitive emulsion. The plane of polarization of a linearly polarized reference beam includes an angle of 45* with its plane of incidence. The beam is reflected under the critical angle of total internal reflection at the lower face of a photographic emulsion. The reflected beam is linearly polarized, too, its plane of polarization being turned by 90*, so that no interference between these two beams is possible. An object beam passes a mask and is linearly polarized vertically either to the reference beam or to the reflected beam so that only one hologram can be formed and no undesired interaction between two holograms is possible when the mask is reproduced for exposure of a photoresist-covered semiconductor wafer.
A method of making a hologram comprising the steps of illuminating an object to produce an object beam of plane polarized light, directing a reference beam of plane polarized light towards a photosensitive emulsion so that it is totally internally reflected within said emulsion such that the reflected reference beam has a plane of polarization orthogonal to the plane of polarization of the incident reference beam, and directing the object beam at said emulsion with its plane of polarization parallel to the plane of polarization of the reflected reference beam so that interference within said emulsion occurs between the object beam and only the reflected reference beam.
Claim 2
Independent Claim
107 words
A method of making a hologram comprising the steps of illuminating an object to produce an object beam of plane polarized light, directing a reference beam of plane polarized light towards a photosensitive emulsion so that it is totally internally reflected within said emulsion such that the reflected reference beam has a plane of polarization orthogonal to the plane of polarization of the incident reference beam, and directing the object beam at said emulsion with its plane of polarization parallel to the plane of polarization of the reflected reference beam so that interference within said emulsion occurs between the object beam and only the reflected reference beam.
Claim 3
Dependent Claim
27 words
A method of making a hologram according to claim 1 wherein said reference beam is linearly polarized at an angle of 45* with its plane of incideNce.