Theory and Design Principles of the Reversible Electroplating Light Modulator

The potential uses and advantages of adjustable light shutters and reflectors based on reversible electroplating on transparent, chemically inert electrodes are indicated briefly. Over the entire visible light range, the highest ratio of optical density change δ to applied charge density appears to be achievable with Ag, especially when formed in conjunction with or ions. An aqueous plating solution containing 3–3.5M AgI and 7M NaI appears to be most suitable for achieving (a) a maximum ratio; (b) a satisfactorily uniform plating; (c) a maximum plating speed; and (d) a maximum rate of unplating. Of several electrode geometries and electrode arrangements capable of yielding essentially uniform plating, those utilizing adjacent subelements composed of parallel, closely spaced, flat, and narrow transparent electrode strips with line‐symmetrically situated contacts is preferred, especially for large‐area modulators. A series connection between the subelements is especially desirable.