Lateral light emitting device and method of producing the same
A lateral light emitting device is formed by fusing one end of a rod lens to an end surface of an optical fiber, and by fusing a prism to another end of the rod lens. The prism has a basic shape including a planar light emitting surface parallel to an axis formed by cutting part of a circumference of a cylinder and has a distal end inclined surface, a distal end portion of which is diagonally cut. Alternatively, a prism lens is fused to the end surface of the optical fiber. The prism lens has the same basic shape described above.
1. A lateral light emitting device comprising:
an optical fiber; and
a prism GRIN lens fused to an end surface of said optical fiber, said prism GRIN lens having:
a planar light emitting surface parallel to a longitudinal axis thereof, said planar light emitting surface being formed by cutting a circumference of a cylinder;
an inclined surface at a distal end of said prism GRIN lens, said inclined surface being formed by diagonally cutting a distal end portion of said prism GRIN lens so that light having entered said prism GRIN, lens from said optical fiber is reflected by said inclined surface and emitted from said light emitting surface.
2. The lateral light emitting device of claim 1 , wherein a furthermost distal end portion of said prism GRIN lens is chamfered.
3. The lateral light emitting device of claim 2 , wherein said furthermost distal end portion is an edge between said light emitting surface and said inclined surface at said distal end.
4. The lateral light emitting device of claim 2 , wherein a maximum diameter of said prism GRIN lens is less than or equal to twice a diameter of said optical fiber.
5. A method of producing the lateral light emitting device of claim 2 , comprising:
forming a ground GRIN lens base material having a planar ground surface parallel to a longitudinal axis of said ground lens base material by cutting a circumference of a cylindrical GRIN lens base material;
forming a fiber for said prism GRIN lens by drawing said ground GRIN lens base material;
fusing said fiber to said optical fiber; and
forming said inclined surface at said distal end by cutting said fiber to form said prism GRIN lens.
6. The method of claim 5 , wherein said forming said fiber for said prism GRIN lens by drawing said ground GRIN lens base material comprises drawing said ground GRIN lens base material at a temperature of about 1800° C.
7. The lateral light emitting device of claim 1 , wherein a maximum diameter of said prism GRIN lens is less than or equal to twice a diameter of said optical fiber.
8. A method of producing the lateral light emitting device of claim 7 , comprising:
forming a ground GRIN lens base material having a planar ground surface parallel to a longitudinal axis of said ground GRIN lens base material by cutting a circumference of a cylindrical GRIN lens base material;
forming a fiber for said prism GRIN lens by drawing said ground GRIN lens base material;
fusing said fiber to said optical fiber; and
forming said inclined surface at said distal end by cutting said fiber to form said prism GRIN lens.
9. The method of claim 8 , wherein said forming said fiber for said prism GRIN lens by drawing said ground lens base material comprises drawing said ground lens base material at a temperature of about 1800° C.
10. A method of producing the lateral light emitting device of claim 1 , comprising:
forming a ground GRIN lens base material having a planar ground surface parallel to a longitudinal axis of said ground lens base material by cutting a circumference of a cylindrical GRIN lens base material;
forming a fiber for said prism GRIN lens by drawing said ground GRIN lens base material;
fusing said fiber to said optical fiber; and
forming said inclined surface at said distal end by cutting said fiber to form said prism GRIN lens.