| abstract |
(57) [PROBLEMS] To provide an optical amplifier which does not require an optical fiber for connection between components constituting the optical amplifier and can be further reduced in size as compared with the conventional one. SOLUTION: At one end of an input optical fiber 1 and an output optical fiber 2, and at both ends of an amplification optical fiber 3, Fiber collimators 4 to 7 are connected to each other, and the amplifying optical fiber 3, the fiber collimators 4 to 7, An optical amplifier is formed by fixing a laser diode 12 for supplying pumping light and an optical multiplexing / demultiplexing filter 11 composed of a dielectric multilayer filter for multiplexing signal light and pumping light on a common substrate 10. In the optical amplifier of the present invention, It is preferable to dispose the microlenses 13, the mirrors 14 to 16 or the prism on the substrate. |