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The report presents the results of rainbow hologram record on photothermoplastic media by He-Ne laser radiation. Hologram characteristics as depended on slit diaphragm width are studied in a case of dimple-natured relief formed on the medium's surface. The recorded holograms are characterized by the value of diffraction efficiency being up to 12% at holographic sensitivity values being not worse than 105cm2/J. Rainbow holography is among the most perspective approaches for visual observation of restored images in polychromatic light. Different media are used for holographic recording, comprising AgHal media, bichromatized gelatine layers, photoresists., chalcogenide vitreous semiconductors and others. Together with these media the use of two-layer photothermoplastic medium (PTPM) com- prised a photosensitive semiconductor layer and visualizing thermoplastic one, seems to be perspective. The characteristic feature of PTPM is a combination of high values of both pho- tosensitivity (up to 105 locro ) and resolution (up to 2000mm-1), developing processes being of a dry nature and rather operative (about 1s). The thinner thermoplastic layer, the higher resonant frequency of PTPM and the wider frequency band of record, allowing to realize the high quality recording of high-frequency holograms. The record of rainbow holograms on PTPM is preferable as well due to the relief-phase nature of recording that is rather convinient for copies making and holographic patterns stamping. To record the rainbow holograms we use the tape PTPM consisted of 1.5pm semiconductor heterostructure, As2S3 As2Se3, and 0.8iim thermoplastic layer based on bytilmethacrylat co-polymer with styren, been deposited in succsession on the metallized PETF-support. The influence of different parameters of PTP recording, such as medium temperature, coroning electrode potential and duration of PTPM charging, on the character of surface deformations forming the relief hologram on PTPM is studied. The diffraction efficiency (DE) of a hologram is found to reach the maximum value at dimple nature of surface deformation. When recording the holograms by making use of such process an interference band is reproduced by dimples arranged in a row; the dimple size is less than 1,um. For the regimes providing a dimple nature of the record (V = 6.2 -÷ 6.8kV, T = 60 + 70C, t = 0.8 + 4.5s) the dependence of DE on spatial frequency is studied.
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