On-chip patterned light source that superimposes multiple patterns for speckle reduction

We have developed an on-chip patterned light source that superimposes multiple beam patterns comprising four elementary pattern areas, with a unique center axis. Each elementary pattern area is designed to emit along the center axis in the far field region, with a trench between each elementary pattern area. The chip size is 800 micrometers square. By comparing the far field pattern of each elementary pattern area, both driven alone and driven together with all elementary pattern areas, we find no blurring, indicating that four elemental images from each elementary pattern area are successfully superimposed, with reduced speckle contrast.