Abstract A photochromic information display and storage device comprises a photochromic target having two absorption states, one of which includes a nondestructive readout band. The target comprises, for example, cerium or lanthanum-doped calcium fluoride crystals. The device also includes means for switching the target from one absorption state to the other and means for directing light in the nondestructive readout band onto the target for the purpose of reading the information stored thereon. The device may also include means for detecting that portion of the light in the nondestructive readout band which is not absorbed by the target and/or means for switching the absorption state of the target back to its original state.
A photochromic display and storage device having a photochromic target comprising a material selected from the group consisting of CaF2:La, CaF2:Ce, and SrTiO3:Co.
Claim 2
Dependent Claim
23 words
A photochromic display and storage device having a photochromic target comprising a material selected from the group consisting of CaF2:La, CaF2:Ce, and SrTiO3:Co.
Claim 3
Dependent Claim
12 words
The device described in claim 1 wherein the photochromic target comprises CaF2:La.
Claim 4
Dependent Claim
12 words
The device described in claim 1 wherein the photochromic target comprises CaF2:Ce.
Claim 5
Dependent Claim
12 words
The device described in claim 1 wherein the photochromic target comprises SrTiO3:Co.