| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a variable attenuation type optical attenuator that has the ability to obtain a target attenuation with a simple configuration, that needs no highly accurate driving mechanism, and that has high setting resolution for attenuation as well as small dependency on wavelength. <P>SOLUTION: The optical attenuator 10 is equipped with a first collimator lens 11 to which an incident optical fiber 21 is connected, a second collimator lens 12 which is connected with a outgoing optical fiber 22 and which is placed in a manner inclined to the first collimator lens 11, and a triangular prism 13 which is disposed between these first and second collimator lenses 11, 12. The triangular prism 13 moves back and forth in the Z direction on an optical path between the first and second collimator lenses 11, 12 by means of an actuator 30. With the triangular prism 13 transferred, a position for bending an optical beam is shifted, so that a light beam entering the second collimator lens 12 is deviated from the center of the lens and that a light beam entering the outgoing optical fiber 22 is made incident in an inclined manner. As a result, the coupling efficiency of the outgoing radiation optical fiber 22 is lowered, thereby increasing the optical attenuation. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
