LED-induced distributed Bragg reflection microwave filter with fiber-optically controlled change of center frequency via photoconductivity gratings

A light-induced distributed Bragg reflection band-reject microwave filter is reported in which the grating elements are optoelectronically generated through periodic-structure photoexcitation of a silicon coplanar waveguide. The center for frequency can be optically adjusted to 11 GHz and 22 GHz by means of a pattern-controlled fiber bundle Array fed from six CW-operated 50-mW, 840-nm light emitting diodes (LEDs). Experimental results are in good agreement with theoretical predictions. The principle of operation demonstrated also applies to millimeter-wave integrated circuits.<
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