| 摘要 |
<p>The present invention provides a small diffractive optical element that emits twisted beam, a small distance measuring apparatus and a distance measuring method using a small diffractive optical element. A diffractive optical element includes a first diffractive grating that twists, in a coordinate space defined by an x-axis, a y-axis and a z-axis, parallel light forming a flat plane parallel to the x-axis and going advance in the z-axis direction so that an angle of the flat plane relative to the x-axis becomes a predetermined angle at a location where the parallel light traveling in the z-axis by a predetermined distance reaches.</p> |
