| 摘要 |
PURPOSE:To obtain multibeams of microspacings by imaging the exit light form a light source array in reduction so as to attain about the diffraction threshold of a condensing optical system determined from the condensing optical system and light source wavelength. CONSTITUTION:This multibeam light source device consists of the light source array 1 arranged with plural light sources 1-a to 1-d consisting of semiconductor lasers and the condensing optical system 2. The plural light beams emitted from the light sources 1 are imaged in reduction by the condensing optical system 2. At this time, the light beams from the plural light sources 1-a to 1-d are focused at a focal plane 3. In such a case, the beam diameter d and spacing L of the respective beams condensing at the focal plane 3 are made small when the reduction rate of the condensing optical system 2 is set high, i.e., when the distance between the condensing optical system 2 and the light source array 1 is taken long. |
