Optera is an optical storage archive technology startup that stores binary digits using the presence or absence of photoluminescence. It does this using spectral hole burning and low-cost lasers, not the expensive femto-second kind as seen with Cerabyte and ewigbyte’s technologies.

We firstwrote about Optera in February this year.

Dr Nick Riesen

The magic lies in the mixed halide fluorobromide/fluorochloride phospho**r **recording medium, known as divalent samarium. The optical researcher behind this, Dr Nicolas Riesen, Adjunct Research Fellow at the University of South Australia, Adelaide, has produced a background document describing the photochemistry and light interactions in more detail.

It involves taking advantage of imperfections in the crystal lattice of a a nanocrystalline system, in this case Ba₀.₅Sr₀.₅FX:Sm²⁺, and altering their photoluminescence characteristics by burning spectral dips or holes. When a laser is scanned across this area it will excite or not excite photoluminescence, and the absence or presence of light can be detected and indicate binary ones and zeros.

The amount of light detected, the depth of the hole as it were, can also be used to encode bits, providing a multi-bit capacity similar to NAND, with its SLC (1), MLC (2), TLC (3), etc. bit quantities indicated by different voltage levels.

Riesen is working on a proof of concept as a first generation of the technology, with a 500 GB capacity planned to be available next year. He foresees a gen 2 with 1 TB capacity in 2027, and a 3 to 5 TB gen 3 around 2030, with tens to hundreds of TB possible by 2035. View this as a series of research POCs, with productization requiring manufacturing partners. The appeal here is that a storage archive using Optera glass tablets would be lower cost and use less energy than one using femtosecond lasers, if the technology works and is manufacturable at the right cost.

A three-page summary document explains this and can be downloaded here.

Bootnote

We understand that Ba₀.₅Sr₀.₅FX:Sm²⁺ (sometimes written as Ba₀.₅Sr₀.₅F₁₋ₓXₓ:Sm²⁺ or Ba₀.₅Sr₀.₅FX:Sm²⁺) is a mixed halide fluorobromide/fluorochloride phosphor doped with divalent samarium ions (Sm²⁺). It is a classic storage phosphor used in computed radiography (CR**)** imaging plates since the 1980s. When scanned with a red laser it emits red light – photostimulated luminescence.