Methods for improving performance of holographic glasses
The improvement of the performance of holographic glasses with recorded holograms as measured by a figure of merit of the holographic glasses is disclosed. The improvement in the figure of merit of the holographic glasses is obtained at least in part with the addition of arsenic in the formation of the holographic glasses. The presence of arsenic increases the figure of merit as measured at a wavelength of interest of a holographic glass with a recorded hologram as compared to a holographic glass with a recorded hologram that does not contain arsenic.
1. An optical element comprising a three-dimensional bulk of a photorefractive, holographic, silicate glass having a Bragg grating recorded therein, wherein the optical element has a figure of merit of at least seven microns when measured for an incident beam of light having a wavelength of 473 nanometers, wherein the figure of merit represents a ratio of photoinduced refractive index modulation to total loss coefficient, and wherein the glass comprises silver, bromine, fluorine, an oxide of cerium, and an oxide of arsenic.
2. The optical element of claim 1 , comprising at least 0.02 percent by weight of the oxide of arsenic.
3. The optical element of claim 1 , comprising 0.02-0.4 percent by weight of the oxide of arsenic.
4. The optical element of claim 1 , comprising 0.05-0.2 percent by weight of the oxide of arsenic.
5. The optical element of claim 1 , wherein the oxide of arsenic is As 2 O 3 .
6. The optical element of claim 1 , wherein the glass is a polychromatic glass.
7. The optical element of claim 1 , wherein the glass is a photo-thermal-refractive glass.
8. The optical element of claim 1 , wherein the optical element has a figure of merit of at least 11 microns when measured for an incident beam of light having a wavelength of 532 nanometers.
9. The optical element of claim 1 , wherein the optical element has a figure of merit of at least 20 microns when measured for an incident beam of light having a wavelength of 633 nanometers.