Variable transmission optical filter

摘要

A method for controlling an amplitude of an incoming light is provided. The method includes attenuating a portion of the incoming light within a first band having a tunable peak attenuation wavelength using a tunable filter; passing a portion of the incoming light from the tunable filter within a second band using a fixed filter; and controlling the amplitude of the incoming light by tuning the peak attenuation wavelength of the tunable filter.

主权项

1. A filter system, comprising:
a tunable filter configured to attenuate via a transmission a portion of an incoming light within a first band having a tunable peak attenuation wavelength; a fixed filter configured to pass a portion of the incoming light from the tunable filter within a second band; a beamsplitter configured to receive and split the portion of the incoming light within the second band from the fixed filter; a detector configured to generate a detection signal based on a magnitude of the split portion of the incoming light directed to the detector by the beamsplitter; and a comparator configured to compare the detection signal with a control signal, and to provide a driving signal to the tunable filter for tuning the peak attenuation wavelength of the tunable filter based on the comparison of the detection signal with the control signal.