A laser communication system for controlling several functions at a location remote to the laser

Claim 1

A remote control system comprising: a laser for producing a laser beam; means for producing a plurality of different frequencies; means for modulating said laser beam with selected ones of said different frequencies; light collector means at a remote location relative to said laser for collecting light in said light beam from 360* in a plane and focusing it on a point; said light collector means comprises a polished surface that conforms to a surface obtained by rotating a segment of one leg of a parabola about an axis through the focus of the parabola and perpendicular to the parabolic axis wherein every point on said segment is a distance from said focus equal to or greateR than the distance along said perpendicular axis from said focus to a point on said parabola whereby all incident light on said surface from a complete 360* in plane parallel to said parabolic axis is brought to a common focus at the focus of said parabola; means for producing an electrical signal indicative of the light at said point; a separate switch associated with each of said plurality of different frequencies; and means responsive to said electrical signal for actuating each of said separate switches whose associated frequency is contained in said electrical signal whereby said plurality of switches can be controlled at said remote location by said modulating means.