Optical information processing device

An optical information processing device that writes and reads information on an information recording medium having:

• a guide layer having a guide track;
• and a plurality of recording layers, the optical information processing device comprising:
• a first light source;
• a second light source;
• a light condensing element that condenses light from the first light source and light from the second light source on the information recording medium;
• a first photodetector that receives light reflected by the information recording medium after being emitted from the first light source and generates a first focusing error signal;
• a second photodetector that receives light reflected by the information recording medium after being emitted from the second light source and generates a second focusing error signal;
• and
• a focusing control circuit that controls the light condensing element by using the first focusing error signal in such a manner that the light from the second light source is condensed on each of the plurality of recording layers in the information recording medium,
• wherein the second focusing error signal is used to add a correction to the focusing control circuit.