| 摘要 |
A tunable interference add/drop filter system combines an interference filter (308) or the like with a mirror (312) attached adjacent to the filter at an angle under 180 DEG to form a reflector assembly (314). The reflector assembly is rotated to tune the filter system. The dropped output (304) passes through the filter, while the passed output (306) reflects off of the filter and the mirror. The direction of the passed output beam is a fixed angle from the input beam, and the beam is translated sideways by a fixed amount, no matter how much the reflector assembly is rotated. Thus the dropped output (or complementary output) can be retained. A null state switch (500) prevents light from reaching the filter while the filter system is tuning. |
