parabolic reflector

1 or parabolic mirror :  a concave mirror that has the form of a paraboloid of revolution so that rays emanating from the geometrical focus and reflected from the surface are all parallel to each other and to the axis of symmetry and rays from a distant source (as a star) are reflected to the focus and that is used in reflecting telescopes, searchlights, and headlights

2 :  a similar device for the directional reflection of microwaves and sound waves