| 摘要 |
An optic system including an integrated variable optical attenuating device for attenuating an input optical signal, the integrated optical variable attenuating device including a first electrically controllable attenuating element and a second electrically controllable attenuating element cascaded together, the first attenuating element having a first range of optical attenuation smaller than that of the second attenuating element but requiring less input power than the second attenuating element to switch between levels of attenuation within the first range of attenuation, and wherein the optic system further includes electrical circuitry for controlling the first and second attenuating elements in coordination with one another so as to achieve the desired level of total attenuation of the optical signal.
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