Photothermally Actuated Self-Tuning Optical Light Valve

A system, comprising:

• a detector;
• and
• an optical filter, including:
• a plate having a top side and a bottom side, the plate having material properties making it transparent to a range of optical frequencies;
• a transparent metasurface proximate the top side of the plate, the transparent metasurface configured to have a transmissive pass band and a stop band;
• and
• an undercarriage support structure proximate the bottom side of the plate, the undercarriage support responsive to photothermal heating;
• the undercarriage support structure configured to deform from the photothermal heating caused by an undesired signal thereby shifting the transparent metasurface stop band in frequency toward the undesired signal to be filtered.

A method of optical filtering, comprising:

• exposing a detector with an optical filter to an undesired signal, the optical filter including a transparent metasurface having a transmissive pass band and a stop band, which is proximate a plate having material properties making it transparent to a range of optical frequencies in the transmissive pass band, which is proximate a undercarriage support;
• deforming the undercarriage support from the photothermal heating caused by the undesired spectral signal;
• shifting the transparent metasurface stop band in frequency toward the undesired signal in response to the deformation of the undercarriage support;
• and
• blocking reception of the undesired signal by the detector.