To provide a structure having a photonic crystal that can display a
reflection function using GR even when a refractive index difference
between a photonic crystal layer and a cladding layer adjacent thereto is
not sufficient and a surface-emitting laser using the structure. The
structure includes a photonic crystal layer including a first member of a
flat shape and plural pillars arrayed two-dimensionally periodically on
the first member. The photonic crystal layer is formed of a first
material having a first refractive index. A low refractive index layer
formed of a second material having a second refractive index lower than
the first refractive index is adjacent to the photonic crystal layer. A
relative refractive index difference between the first refractive index
and the second refractive index is not less than 0.04 and does not exceed
0.13. The height of the pillars with respect to the thickness of the
photonic crystal layer is not less than 0.10t and does not exceed 0.07t.