A tunable optical filter includes a tunable Fabry-Perot filter, two tunable waveguide Bragg gratings and a 2\xd72 3-dB coupler. The control device includes a plurality of electromagnetic valves, a plurality of application pressure control valves, a selector, and a line pressure control valve. The open fields are preferably stored as a voice mail domain summary in the e-mail directory of the unified messaging system. For example, versioned write locks are used with parallel nested transactions. The receiver is capable of receiving the subject information within a predetermined range around an optical axis of the image taking lens.