APPARATUS FOR MEASURING GAP OF SOLID IMMERSION LENS

摘要

PURPOSE: A gap measuring apparatus for a solid immersion lens is provided to easily measure a gap formed between a storage medium and the solid immersion lens by detecting a distribution of interference signals. CONSTITUTION: A gap measuring apparatus includes a refracting device(201), and a light detecting device(202). The refracting device(201) allows internal total-reflection light(204) reflected from a lower plane(104a) of a solid immersion lens and transmission light(205) reflected from a surface of a storage medium(105) to be focused at one spot. The light detecting device(202) detects a light intensity distribution of an interference signal generated by the refracting device(201). The refracting device(201) includes at a refractive optical device having at least one lens. The light detecting device(202) includes photoelectronic device or a charge coupled device.