Patent ID: 6114698
Filing Date: 2000-09-05
Classification: G01J

Abstract:
A pyroelectric detector having reduced sensitivity to acoustic noise comprising:a z-cut electret having a front surface and a rear surface and having a first and second domain region;said first domain region having a spontaneous polarization;said second domain region having a spontaneous polarization opposite to the spontaneous polarization of said first domain region, said spontaneous polarization aligned in said second domain region by application of a electric field across said electret to form high resolution domain boundaries, said first and second domain regions thereby comprising a detector region;a first electrode attached to said front surface spanning substantially equal portions of each domain region; anda second electrode attached to said rear surface spanning said domain regions that are the same domain regions that are spanned by said first electrode to define a detector region and to reduce sensitivity to said acoustic noise by conductively combining the acoustic responses of said first and second domain regions;an electrically conductive container connected to a ground potential that receives said electret, said container having an opening for receiving incident radiation and held at ground potential to provide electrical shielding; andsaid first electrode being conductively connected to said container about a perimeter of said opening in said container such that said first electrode is aligned with said opening in said container to receive incident radiation and said first electrode is grounded to said electrically conductive container.