Abstract: A recording member having a predetermined substrate, and a thin film which is formed on the substrate and which is formed with recesses or pits for recording information when irradiated with a working beam, characterized in that said thin film is formed of an inorganic material which contains at least arsenic, selenium and tellurium, and that a distribution of either of said Se and said Te decreases from a part near the surface of said thin film towards a central part thereof, while a distribution of said As increases from a part near the surface towards said central part, is disclosed. This recording member can afford a high signal-to-noise ratio and a long lifetime.

Abstract: An optical head comprising a lens disposed at a position for forming spot images of a semiconductor laser having a plurality of lasing points, in which beams from the semiconductor laser are focused on a disc on which predetermined information is recorded by light.

Abstract: A recording member in which a bismuth-antimony alloy thin film containing antimony as its indispensable component is deposited on a predetermined substrate is disclosed. The Sb content of the film lies in a range of from 1 % to 15 % inclusive in terms of the average atomic-%. Preferably, the Sb content has the average value held in the specified range, and it is gradually increased in the thickness direction of the film so that in the part near the substrate and/or front surface of the film, the maximum content may lie within a range of at most three times the average content of other part of the film.

Abstract: An optical information recording and reproducing apparatus is disclosed in which a predetermined signal is recorded on a track of a rotating recording medium by a recording light beam and the recorded information is reproduced by a reproducing light beam. The information recorded on the last record track is reproduced by the recording beam and the reproducing beam and radiating position of the recording beam on the recording medium is displaced by a predetermined distance from the last record track.