Evanescent light generation element and evanescent light generation device

An evanescent light generation element for oscillating evanescent light from an optical waveguide to a clad layer:

• said element comprising:
• a thin layer comprising a ferroelectric single crystal or oriented crystal, having a thickness of equal to or more than 0.4 μm and equal to or less than 2 μm and comprising a first principal surface, a second principal surface, an incident side end surface and an exit side end surface;
• a ridge optical waveguide formed in said thin layer and extending between said incident side end surface and said exit side end surface of said thin layer;
• at least a pair of grooves formed on both sides of said ridge optical waveguide in said thin layer and opening at said first principal surface of said thin layer;
• a support substrate bonded to said first principal surface by one of direct bonding and a bonding layer;
• and
• a clad layer provided on said second principal surface;
• wherein a width of said ridge optical waveguide at said exit side end surface is less than a width of said ridge optical waveguide at said incident side end surface, said width of said ridge optical waveguide at said exit side end surface being smaller than 1 μm and larger than zero;
• wherein a light propagating in said ridge optical waveguide consists essentially of a linearly polarized optical wave polarized in a normal direction of said second principal surface of said thin layer;
• wherein said light propagating in said ridge optical waveguide is emitted from said exit side end surface;
• and
• wherein said evanescent light is obtained from said clad layer.