HIGHLY DISPERSIVE OPTICAL ELEMENT WITH BINARY TRANSMISSIBILITY
The current application is directed to a new, highly dispersive optical element that is characterized by binary transmissibility. Various alternative implementations of the new optical element (“NOE”) are fashioned from semiconductor materials, including binary III-V and II-VI semiconductor materials. When applied as components within various optical devices and systems, the NOEs are fashioned to have shapes that provide high dispersion at non-extreme exit angles. The NOEs are additionally coated with multiple anti-reflective coatings which facilitate high transmission, in excess of 90 percent, across a wide range of visible and infrared wavelengths.
1 . An optical component of an optical system, the optical component comprising:
a semiconductor material that transmits 90% or greater of incident visible light above a threshold wavelength in the ultraviolet or visible electromagnetic-radiation band;
an input optical surface and an output optical surface; and
multiple anti-reflective coatings layered on the input optical surface and the output optical surface, the multiple anti-reflective coatings having refractive indexes greater than the refractive index of a medium external to the optical component and less than the refractive index of the semiconductor material, the refractive indexes of the multiple anti-reflective coatings increasing from outermost to innermost so that no adjacent coating layers have a difference in refractive index greater than 0.1.
2 . The optical component of claim 1 wherein the semiconductor material is a binary II-VI semiconductor material.
3 . The optical component of claim 2 wherein the semiconductor material is one of:
ZnSe;
ZnS.
4 . The optical component of claim 1 wherein the semiconductor material is a binary III-V semiconductor material.
5 . The optical component of claim 1 wherein the semiconductor material is ONE OF:
ThBrI 2 ;
IV-VI telluride oxides;
alkali yttrium oxides;
I-III-VI lanthanide oxides; and
ZnCdTe 2 .
6 . The optical component of claim 1 wherein the semiconductor material is doped with one of an acceptor dopant and a donor dopant.
7 . The optical component of claim 1 wherein the type and amount of dopant within the semiconductor material determines the threshold wavelength below which incident light is blocked and above which incident light is transmitted.
8 . The optical component of claim 1 wherein the optical component has an etendue at least two times greater than the etendue of a similarly sized and shaped glass optical component.
9 . The optical component of claim 1 wherein the median index of refraction for the multiple anti-reflective coatings is approximately equal to the square root of the refractive index of the semiconductor material.
10 . The optical component of claim 1 wherein the optical component receives incident light at near the Brewster's angle for glass.
11 . The optical component of claim 1 wherein the optical component disperses visible incident light over an angle at least three times greater than the angle over which a similarly sized and similarly shaped glass optical element disperses visible light.
12 . The optical component of claim 1 wherein the optical component disperses visible incident light over an angle at least ten times greater than the angle over which a similarly sized and similarly shaped glass optical element disperses visible light.
13 . The optical component of claim 1 wherein the optical component disperses visible incident light over an angle at least ten times greater than the angle over which a similarly sized and similarly shaped glass optical element disperses visible light.
14 . The optical component of claim 1 wherein the rate of change of etendue with respect to the wavelength of incident light for the optical component is greater than 10 times the rate of change of etendue with respect to the wavelength of incident light for a similarly sized and similarly shaped glass optical component.
15 . The optical component of claim 1 wherein, at wavelengths 5 nm or more below the threshold wavelength, the optical element transmits less than one part in 10 12 of the light transmitted at wavelengths 5 nm or more above the threshold wavelength.
16 . The optical component of claim 1 wherein, at wavelengths 2 nm or more below the threshold wavelength, the optical element transmits less than one part in 10 12 of the light transmitted at wavelengths 2 nm or more above the threshold wavelength.
17 . The optical component of claim 1 wherein, at wavelengths 5 nm or more below the threshold wavelength, the optical element transmits less than one part in 10 14 of the light transmitted at wavelengths 5 nm or more above the threshold wavelength.
18 . The optical component of claim 1 wherein, at wavelengths 2 nm or more below the threshold wavelength, the optical element transmits less than one part in 10 14 of the light transmitted at wavelengths 2 nm or more above the threshold wavelength.
19 . An optical element comprising:
a semiconductor material that transmits 90% or greater of incident visible light above a first threshold wavelength in the ultraviolet or visible electromagnetic-radiation band and that transmits less than one part in 10 12 of incident visible and UV light below a second threshold wavelength in the ultraviolet or visible electromagnetic-radiation band, the first and second thresholds separated in wavelength by less than 5 nm;
an input optical surface and an output optical surface; and
multiple anti-reflective coatings layered on the input optical surface and the output optical surface, the multiple anti-reflective coatings having refractive indexes greater than the refractive index of a medium external to the optical component and less than the refractive index of the semiconductor material, the refractive indexes of the multiple anti-reflective coatings increasing from outermost to innermost so that no adjacent coating layers have a difference in refractive index greater than 0.15.
20 . The optical element of claim 19 wherein the input and output optical surfaces are each one of planar;
convexly curved; and
concavely curved.