초록 ▼

A low weight, achromatic, athermal, long wave infrared objective lens with one element having a positive optical power and the other element having a negative optical power but with a higher thermo-optic coefficient than the thermo-optic coefficient of the first element. A diffractive color correcti

A low weight, achromatic, athermal, long wave infrared objective lens with one element having a positive optical power and the other element having a negative optical power but with a higher thermo-optic coefficient than the thermo-optic coefficient of the first element. A diffractive color correcting optical surface is generated on one surface of one of the elements and aspheric surfaces may be included for further performance gains.

대표청구항 ▼

[ I claim:] [1.] A low weight, athermal, color corrected objective lens for use in any portion of the 8 to 12 um spectral band generated by an IR source and consisting of,a first optical lens element having positive optical power nearest the source,a second optical lens element having negative optic

[ I claim:] [1.] A low weight, athermal, color corrected objective lens for use in any portion of the 8 to 12 um spectral band generated by an IR source and consisting of,a first optical lens element having positive optical power nearest the source,a second optical lens element having negative optical power between the first optical lens element and its focal plane,the lens material of said second optical lens element having a higher thermo-optic coefficient than the thermo-optic coefficient of the lens material of said first optical lens element and,a diffractive surface generated on one surface of one of said lens elements for color correction so that the entire spectral band of 8 to 12 um is in focus at said focal plane.