| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a conventional art VIPA (Virtually Imaged Phased Array) has caused deterioration of a binding rate of light when an optical signal returns to the same or different VIPA for a profile of interference light or a size of optical system components has enlarged, and when converging the interference light within a certain range by a lens, in comparison with a Gaussian beam obtained by an oscillation element or a wavelength dispersion element, or the like, a beam expanded to a broad range has to be handled, and thereby, a size of optical system components has been enlarged.SOLUTION: A wavelength dispersion element according to the present invention is configured to obtain a beam profile of desired interference light by making reflectance of at least one of two reflection films consisting of a VIPA uneven. The beam profile of the interference light is configured to be formed into a symmetry shape with respect to an axis in an advancement direction, and thereby a binding loss is reduced. The reflectance of the reflection film is configured to be able to be set so that a light intensity distribution of the interference light emerging from the reflection film has a profile of any of a Gaussian distribution, a rectangle function distribution or a sinc function distribution on the axis perpendicular to an emerging direction of the interference light. |
