Optical device

An optical device comprising:

• a first mirror having a first planar surface;
• a second mirror spaced from the first mirror in a first direction crossing the first planar surface, the second mirror having a concave surface including a first region and a second region around the first region, a first distance between the first region and the first planar surface in the first direction being longer than a second distance between the second region and the first planar surface in the first direction, and the first distance being half or less of curvature radius of the concave surface;
• a first member being light transmissive, being solid, and including a first portion provided between the first mirror and the second mirror, the first portion being in contact with the first planar surface and the concave surface;
• a second member being light transmissive, the second member not overlapping the second mirror in the first direction;
• and
• a third member being light transmissive, the third member not overlapping the second mirror in the first direction, the first member being located between the second member and the third member in a second direction crossing the first direction.

An optical device comprising:

• a first mirror having a first concave surface including a first region and a second region provided around the first region;
• a second mirror spaced from the first mirror in a first direction, the second mirror having a second concave surface including a third region and a fourth region provided around the third region, first distance between the first region and the third region in the first direction being longer than second distance between the second region and the fourth region in the first direction, and the first distance being 0.5 times or less of sum of curvature radius of the first concave surface and curvature radius of the second concave surface;
• a first member being light transmissive, being solid, and including a first portion provided between the first mirror and the second mirror, the first portion being in contact with the first concave surface and the second concave surface;
• a second member being light transmissive, a second direction from the first member toward the second member crossing the first direction, the second member not overlapping the second mirror in the first direction;
• a third member, part of the first mirror being located between the first member and the third member in the first direction;
• and
• a fourth member, a direction from the third member toward the fourth member being along the second direction, another part of the first mirror being located between the second member and the fourth member in the first direction.

An optical device comprising:

• a first mirror having a first planar surface;
• a second mirror spaced from the first mirror in a first direction crossing the first planar surface, the second mirror having a concave surface including a first region and a second region around the first region, a first distance between the first region and the first planar surface in the first direction being longer than a second distance between the second region and the first planar surface in the first direction, and the first distance being half or less of curvature radius of the concave surface;
• a first member being light transmissive, being solid, and including a first portion provided between the first mirror and the second mirror, the first portion being in contact with the first planar surface and the concave surface;
• a second member being light transmissive, a second direction from the first member toward the second member crossing the first direction, the second member not overlapping the second mirror in the first direction;
• and
• a first prism being spaced from the second mirror in the second direction, the first prism overlapping part of the second member in the first direction.