Illumination device

An illumination device comprising:

• an optical fiber having a first end portion and a second end portion opposite to the first end portion, the optical fiber allowing light emitted from a light source to be introduced at the first end portion thereof and to be guided through the optical fiber while emitting a portion of the light through a side surface of the optical fiber;
• a light-transmissive tube having a first end portion and a second end portion opposite to the first end portion, the light-transmissive tube covering the side surface of the optical fiber such that a gap is located between the tube and the side surface of the optical fiber;
• and
• a light-shielding cap covering the second end portion of the tube at a side opposite the light source such that a space is located between a bottom portion of the cap and the second end portion of the tube,
• wherein the second end portion of the optical fiber projects past the second end portion of the tube and is located at an inner side of the cap.