Holographic information recording/reproducing apparatus

A holographic information recording/reproducing apparatus comprising:

• a light source;
• a splitter unit that splits a light beam from the light source into a first light beam and a second light beam;
• a spatial light modulator that makes the first light beam bear information;
• a first galvano mirror that reflects the second light beam toward an information recording medium;
• a second galvano mirror that makes the second light beam coming out from the information recording medium reenter the information recording medium;
• and
• a controller that controls the angle of the first galvano mirror and that of the second galvano mirror,
• wherein the controller controls the first galvano mirror and the second galvano mirror so as to establish relationships of θ1≠θ2 and θ1=θ3, where
• θ1 is the angle of incidence of the second light beam entering the information recording medium at the time of recording;
• θ2 is the angle of incidence of the second light beam entering the information recording medium at the time of reproduction;
• and
• θ3 is the angle of incidence of the second light beam reentering the information recording medium at the time of reproduction.