The Spatial Photographic Recording of Fine Interference Phenomena*

Interference bands as close together as 0.4μ were recorded with the Kodak Type 548 Spectroscopic Plates. The penetration of these bands into the emulsion layer was detected by microscopic examination of a vertical section of the photographic record. The photographic record of such bands, the spacing between which depends only upon the angular tilt of a Lloyd mirror and the wave-length of the radiant energy being used, should prove useful as a stage micrometer. Since these photographic records behave as diffraction gratings, the spacing between the band images was checked by measuring the diffraction angle, using radiant energy having a wave-length shorter than the spacing.