1. A laser driven lamp configured to enclose light emitting gas, receive a converging laser beam and generate plasma from the laser beam, the laser driven lamp comprising:a main body having a columnar shape;
a concave reflecting portion formed at a front side of the main body, the concave reflecting portion having a focal point at which the laser beam converges;
a light exit window provided in front of the concave reflecting portion;
a laser beam passing hole formed at a center of the main body, the laser beam passing hole penetrating the main body in an optical axial direction of the lamp;
a light entrance window provided at a rear side of the main body, the laser beam being incident to the light entrance window; and
a tapered part at a light incident side of the laser beam passing hole in the main body,
the main body, the light exit window and the light entrance window constituting in combination a closed space, and
the light emitting gas being enclosed in the closed space.