An information processing apparatus comprising: a photo-detecting section configured to receive reflected light from a disk; and a signal processing section configured to generate a reproduced signal by performing signal processing on a light reception signal from the photo-detecting section, wherein the disk comprises: a carrier signal formed by carrier grooves in a regularly periodic protruding and recessing pattern formed in advance on the disk, said pattern having a high frequency higher than or equal to a cut-off frequency, which is defined as Fc=2NA/A, where λ stands for the wavelength of the laser beam from the optical pickup and NA for the numerical aperture of the lenses constituting the optical pickup; and a record signal which is recorded by forming marks over said regularly periodic protruding and recessing pattern, wherein the photo-detecting section has two split detectors A and B in a direction of tracks on the disk, wherein the signal processing section generates a TPP (Tangential Push-pull) signal made of a differential signal derived from detection signals from the detectors A and B, the TPP signal being obtained as a readout signal by frequency-shifting a superimposed signal having the carrier signal and the record signal superimposed with each other, and wherein the signal processing section generates the reproduced signal through extraction of a high-frequency component range from the record signal recorded on the disk by performing an operation of frequency-shifting the generated TPP signal to the high-frequency component range in the record signal recorded on the disk, wherein the operation is a process of multiplying the TPP signal with the carrier signal, wherein the signal processing section performs the process of multiplying the TPP signal with the carrier signal in order to frequency-shift the TPP signal to the high-frequency component range in the record signal recorded on the disk, and wherein the signal processing section generates the reproduced signal by performing a process of combining a sum signal summing up the detection signals from the detectors A and B, with the TPP signal from which the component of the carrier signal is removed so as to correspond to the record signal. a photo-detecting section configured to receive reflected light from a disk; and a signal processing section configured to generate a reproduced signal by performing signal processing on a light reception signal from the photo-detecting section, wherein the disk comprises: a carrier signal formed by carrier grooves in a regularly periodic protruding and recessing pattern formed in advance on the disk, said pattern having a high frequency higher than or equal to a cut-off frequency, which is defined as Fc=2NA/A, where λ stands for the wavelength of the laser beam from the optical pickup and NA for the numerical aperture of the lenses constituting the optical pickup; and a record signal which is recorded by forming marks over said regularly periodic protruding and recessing pattern, a carrier signal formed by carrier grooves in a regularly periodic protruding and recessing pattern formed in advance on the disk, said pattern having a high frequency higher than or equal to a cut-off frequency, which is defined as Fc=2NA/A, where λ stands for the wavelength of the laser beam from the optical pickup and NA for the numerical aperture of the lenses constituting the optical pickup; and a record signal which is recorded by forming marks over said regularly periodic protruding and recessing pattern, wherein the photo-detecting section has two split detectors A and B in a direction of tracks on the disk, wherein the signal processing section generates a TPP (Tangential Push-pull) signal made of a differential signal derived from detection signals from the detectors A and B, the TPP signal being obtained as a readout signal by frequency-shifting a superimposed signal having the carrier signal and the record signal superimposed with each other, and wherein the signal processing section generates the reproduced signal through extraction of a high-frequency component range from the record signal recorded on the disk by performing an operation of frequency-shifting the generated TPP signal to the high-frequency component range in the record signal recorded on the disk, wherein the operation is a process of multiplying the TPP signal with the carrier signal, wherein the signal processing section performs the process of multiplying the TPP signal with the carrier signal in order to frequency-shift the TPP signal to the high-frequency component range in the record signal recorded on the disk, and wherein the signal processing section generates the reproduced signal by performing a process of combining a sum signal summing up the detection signals from the detectors A and B, with the TPP signal from which the component of the carrier signal is removed so as to correspond to the record signal.