HIGH GAIN COATINGS AND METHODS
A halogen incandescent burner comprising a quartz body comprising a light emitting chamber, a filament positioned within the light emitting chamber, and a multilayer optical coating on at least a portion of the chamber. The coating may include a plurality of layers of a low refractive index material and a high refractive index material having a total thickness of at least nine microns, wherein the gain of the burner is at least 1.7. The high refractive index material may comprise tantala and the low refractive index material may comprise silica.
1 . A halogen incandescent burner comprising:
a quartz body comprising a light emitting chamber;
a filament positioned within said light emitting chamber; and
a multilayer optical coating on at least a portion of said chamber, said coating comprising a plurality of layers of a low refractive index material and a high refractive index material having a total thickness of at least nine microns,
wherein the gain of said burner is at least 1.7.
2 . The burner of claim 1 wherein said high refractive index material comprises tantala.
3 . The burner of claim 1 wherein said low refractive index material comprises silica.
4 . The burner of claim 1 wherein said coating comprises alternating layers of tantala and silica.
5 . The burner of claim 4 wherein said burner operates with a luminous efficiency of at least forty lumens per watt over at least one thousand hours of operation.
6 . The burner of claim 1 wherein said burner operates with a luminous efficiency of at least thirty lumens per watt over at least five-hundred hours of operation.
7 . The burner of claim 6 wherein said burner operates with a luminous efficiency of at least thirty lumens per watt over at least one thousand hours of operation.
8 . The burner of claim 6 wherein said burner is rated at sixty watts and operates with a luminous efficiency of about forty-three lumens per watt over at least one thousand hours of operation.
9 . The burner of claim 1 having an average reflectance over the range of wavelengths from 800 nm to 1500 nm of at least 97.
10 . The burner of claim 1 used as a light source in a type of lamp selected from the group consisting of an A-line lamp, a general service lamp, a modified spectrum lamp, a reflector lamp, a parabolic reflector lamp, an ER/BR lamp, and a torchiere.
11 . The burner of claim 1 wherein said coating comprises alternating layers of tantala and silica having a total thickness of at least eleven microns and wherein the gain of said burner is at least 1.85.
12 . The burner of claim 1 forming a double-ended burner.
13 . The burner of claim 1 forming a single-ended burner.
14 . The burner of claim 1 wherein said coating comprises alternating layers of tantala and silica having a total thickness of at least eleven microns.
15 . A halogen incandescent burner having an infrared reflecting coating on at least a portion thereof, said coating comprising alternating layers of tantala and silica and having a total thickness of greater than nine microns and a gain of at least 1.7.
16 . The burner of claim 15 wherein said coating comprises alternating layers of tantala and silica and has a total thickness of at least eleven microns and a gain of at least 1.85.
17 . A halogen incandescent burner having an infrared reflecting coating on at least a portion thereof, said coating comprising alternating layers of tantala and silica and having a total thickness of greater than nine microns and an average reflectance over the range of wavelengths from 800 nm to 1500 nm of at least 97.
18 . The burner of claim 17 wherein said coating comprises alternating layers of tantala and silica and has a total thickness of at least eleven microns.
19 . A halogen incandescent burner having an infrared reflecting coating on at least a portion thereof, said coating comprising alternating layers of tantala and silica and having a total thickness of greater than nine microns and a luminous efficiency of at least thirty lumens per watt over at least five hundred hours of operation.
20 . The burner of claim 19 wherein said burner operates with a luminous efficiency of at least thirty lumens per watt over at least one thousand hours of operation.
21 . The burner of claim 20 wherein said burner operates with a luminous efficiency of about forty-three lumens per watt over at least one thousand hours of operation.
22 . The burner of claim 19 wherein said coating comprises alternating layers of tantala and silica and has a total thickness of at least eleven microns.
23 . A method of improving the lumens per watt of a halogen incandescent burner comprising sputter coating at least a portion of the burner with a multilayer infrared reflecting coating having alternating layers of tantala and silica a total thickness of at least nine microns.
24 . The method of claim 23 wherein the gain is at least 1.7.
25 . The method of claim 23 wherein the lumens per watt of the burner with the coating is at least thirty over at least the first five hundred hours of operation of the burner.
26 . method of claim 25 wherein the lumens per watt of the burner with the coating is at least forty over at least the first one thousand hours of operation of the burner.
27 . The method of claim 23 wherein the average reflectance of the coating over the range of wavelengths from 800 nm to 1500 nm is at least 97.
28 . A method comprising:
providing a lamp burner having a quartz body forming a light emitting chamber housing an incandescent filament;
sputter coating at least a portion of the light emitting chamber to thereby form a multilayer infrared reflecting coating having a plurality of layers of tantala and silica and a total thickness of at least nine microns,
wherein the gain realized by coating the burner is at least 1.7.
29 . The method of claim 28 wherein said sputter coating includes forming alternating layers of tantala and silica.