Light irradiation device

A light irradiation device comprising:

• a Gaussian beam output unit configured to output light having an intensity distribution that conforms to a Gaussian distribution;
• a spatial light modulator configured to receive the light and modulate the light by presenting a computer generated hologram;
• an optical system configured to converge the modulated light;
• and
• an amplitude mask arranged on at least one of an optical axis between the Gaussian beam output unit and the spatial light modulator and an optical axis between the spatial light modulator and the optical system,
• wherein the amplitude mask has a circular-shaped first region centered on the optical axis and an annular-shaped second region that surrounds the first region, and
• wherein a light intensity of a part of the light transmitted through the second region continuously decreases as a distance from the optical axis increases.