Manufacturing method for hologram which can prevent the formation of ghant holograms due to noise light

The manufacturing method for a hologram, comprising the steps of:

• forming a master hologram by:
• holding a substrate for hologram formation on a first side with a first prism having a vertical angle .psi..sub.1 and on a second side with a second prism having a vertical angle .psi..sub.2, said substrate having a hologram photosensitive layer;
• and
• irradiating a reference light from a first prism side to said substrate while irradiating an object light from a second prism side to said substrate, whereby an interference fringe is formed on said hologram photosensitive layer of said substrate,
• wherein said reference light is a P-polarized light, and a relation between said vertical angles .psi..sub.1 and .psi..sub.2 of the prisms and an incident angle .theta. of said reference light is set so that an angle a between reference light reflected from a surface of said second prism and said reference light traveling in said substrate is approximately a right angle;
• forming an interference fringe on a hologram photosensitive layer provided on the substrate for reproduction by a reference light and a reproduced light of said master hologram to thereby produce a replica hologram of said master hologram, wherein said reproduced light is formed from said reference light transmitted through said substrate;
• preparing a prism for reproduction having the same vertical angle .psi..sub.1 as a vertical angle of the first prism;
• disposing said substrate for reproduction on a first surface forming said vertical angle of said prism for reproduction;
• and
• disposing said master hologram on a second surface forming said vertical angle;
• wherein said interference fringe forming step includes a step of irradiating said reference light which comprises light incident at the same angle as the light used for manufacturing said master hologram, said reference light being irradiated from said first surface of said prism for reproduction, and whereby said interference fringe is formed on said hologram photosensitive layer of said substrate for reproduction due to said reference light and said reproduced light, said reproduced light comprising reference light diffractively reflected by said master hologram.