Optical switch and display unit

A display unit comprising:

• an optical waveguide for receiving light containing a specific polarized light component as incident light;
• a light emergence portions crossing said optical waveguide;
• and
• an optical switch, disposed between said waveguide and said light emergence portion, for making at least a portion of said incident light selectively emergent from said optical waveguide to said light emergence portion;
• wherein said optical switch has a light transmissive stacked structure including a function layer for selective emergence of said incident light;
• and
• letting Δn be a difference between a refractive index no of said optical waveguide and a refractive index nl of an arbitrary layer forming part of said stacked structure, “d” be a thickness of said arbitrary layer, and λ be a wavelength of said incident light, the values of Δn, “d”, and λ satisfy a condition of 2.20×10−3≦|Δn·d·λ−1|≦3.03×10−3;
• and
• the functional layer of said optical switch has a length, L, in the longitudinal direction of the optical waveguide and said optical waveguide has a thickness in a range of 0.05·L μm to 0.2·L μm.