摘要 |
A device having a case, an input optical fiber and an output optical fiber and a light path extending between the input and output optical fiber. A light path interrupting element is disposed within the case and is movable from a first position at which it interrupts a portion of the light path so that a first amount of light can reach the output optical fiber to a second position at which a second amount of light can reach the output optical fiber. A retainer is moveable relative to the case from a retaining position to a disengaged position. At the retaining position the retainer is engaged with the light path interrupting element to retain the light path interrupting element at the first position, and at the disengaged position the retainer is disengaged from the light path interrupting element and the light path interrupting element is at the second position. |