Optical notch filter utilizing electric dipole resonance absorption
AssigneeThe Unites States of America as represented by the Secretary of the Navy
InventorsDonald L. Decker, William M. Tolles
Life of this patent
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Abstract
An optical notch filter having a suspension of small absorbing particles which blocks a narrow band of frequencies. The small absorbent particles are suspended as a colloidal system which can have either a solid, liquid or gas as host material. The absorbing particles can be incorporated in a solid matrix as a transmission filter or used on the surface of a mirror as a reflection filter. The filter can be tuned by an externally applied electric field or by applying hydrostatic pressure.
Claims22
An optical notch filter comprising:
- a suspending material wherein said suspending material comprises a material selected from the group consisting of air, KBr, NaF, CaF.sub.2, BaF.sub.2, LiF, KCl, NaCl, KRS-5 and ZnSe;
- and
- a plurality of absorbing particles within said suspending material to form a colloidal system, said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength.
An optical notch filter comprising:
- a suspending material;
- and
- a plurality of absorbing particles within said suspending material to form a colloidal system, said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength.
- wherein said absorbing particles comprise a material selected from the group consisting of MgO, BeO, .alpha.Al.sub.2 O.sub.3, BN, Ag.sub.1-x Cd.sub.x alloy system, Ag.sub.1-x Zn.sub.x alloy system and Ag.
An optical notch filter comprising
- a suspending material;
- a plurality of absoring particles within said suspending material to form a colloidal system, said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength;
- and
- means for tuning said filter.
A method for producing an optical notch filter comprising the steps of:
- mulling a plurality of absorbing particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength, together with a finely ground powder of a suspending material without changing the character of said absorbing particles;
- and
- pressing said mulled powder mixture in a vacuum to form a solid matrix.
An optical notch filter comprising;
- a suspending material selected from the group consisting of air, KBr, NaF, CaF.sub.2, BaF.sub.2, LiF, KCl, NaCl, KRS-5 and ZnSe;
- and
- a plurality of absorbing particles within said suspending material to form a colloidal system said particles having a dielectric constant such that a resonant absorption condition exists for a given wavelength of incident radiation, and being small in size relative to said wavelength, wherein said absorbing particles are selected from the group consisting of MgO, BeO, .alpha.Al.sub.2 O.sub.3, BN, Ag.sub.1-x Cd.sub.x alloy system, Ag.sub.1-x Zn.sub.x alloy system and Ag.
Dependencies are inferred from the claim text.