PICKUP FOR PHOTOMAGNETIC RECORDING AND REPRODUCING DEVICE OF SIMULTANEOUS ERASING AND RECORDING TYPE

PURPOSE:To record and reproduce information with one pit in the simultaneous erasing and recording type and monitor information at the recording time by using beams different in wavelength at the recording time as well as the reproducing time. CONSTITUTION:A laser light source 1 emits a polarized beam Bw having a wavelength lambdaw, and a laser light source 2 emits a polarized beam Bm having a wavelength lambdam. A beam splitter BS 3 allows optical axes of irradiated light to a recording medium S of beams Bm and Bw to coincide with each other. A quarter-wave plate 4a is provided on the first face of a PBS 4, and a reflecting layer 4b is provided on the outside of this plate 4a and a quarter-wave plate 4c is provided on the second face of the PBS 4, and the first interference filter 4b which permits the beam Bm to transmit through bus reflects the beam Bw is provided on the outside of this plate 4c. The BS 3 and the PBS 4 are so arranged that their azimuth angles gamma to the reference plane of polarization is 0, and directions of the PBS 4 and the BS are equalized.