OPTICAL MULTIPLEXER MEMBER, LIGHT SOURCE UNIT, ILLUMINATION DEVICE, AND IMAGE PROJECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an optical multiplexer member that achieves a reduction in size and can multiplex two or more rays of light at low optical loss.SOLUTION: There is provided an optical multiplexer member that includes a light propagation unit having a plurality of optical paths and an optical multiplexing unit optically coupled to the light propagation unit, where the light propagation unit has a plurality of first cores 2 being the optical paths and a first clad 3 having a lower refractive index than that of the first cores 2 and provided to cover at least two substantially opposing faces of the first cores 2; the optical multiplexing unit has a second core 5 multiplexing rays of light propagated by the light propagation unit and propagating the resulting light and a second clad 6 having a lower refractive index than that of the second core 5 and provided to cover at least two substantially opposing faces of the second core 5; the difference in refractive index between at least one or more first cores 2 and the first clad 3 is smaller than the difference in refractive index between the second core 5 and the second clad 6.