摘要:
Beam shaping means may have a shaping ratio set to allow a light beam emitted from a semiconductor laser and having an elliptic intensity distribution to have an ellipticity of no more than two to obtain a spot achieving high light availability and reduced in size. Furthermore, the shaping ratio can be set to no more than 2.5 to allow a polalized-beam splitter (light separation means) and other components to be arranged in a converged flux passing between the semiconductor laser and a collimator lens.
摘要:
In an optical recording medium, a groove G and/or a land L composing a recording track includes an interrupted portion of a predetermined length in a direction of the recording track, and the interrupted portion is a clock mark to obtain a clock signal. When (clock mark length C1)/(beam spot size D1)=CM, CM≦1.0. This reduces a region to record the control signal, thereby enabling high-density recording and reproduction, reproducing a control signal having a waveform free from distortion, and generating a clock signal in a state of little jitter.