Glass memory: femtosecond-laser archival storage achieves ultra-dense, millennia-durable data
Microsoft Research’s Silica demonstrates an end-to-end optical archival storage system that writes data into glass using two voxel regimes. Birefringent voxels in fused silica (pseudo-single-pulse) yield 1.59 Gbit/mm^3 density, about 4.84 TB per platter, at 25.6 Mbit/s per beam with 10.1 nJ/bit; phase voxels in borosilicate glass (single-pulse) reach 0.678 Gbit/mm^3, about 2.02 TB per platter, at 18.4 Mbit/s and 8.85 nJ/bit. A multibeam setup attains 65.9 Mbit/s. Data are read with wide-field microscopy and decoded by a CNN-based symbol-inference pipeline plus LDPC error correction, enabling error-free recovery across billions of voxels. Accelerated ageing tests project data lifetimes exceeding 10,000 years at room temperature. The fully automated write/read/decode chain, plus scaling directions (higher NA, more beams, different glasses), position Silica as a durable, high-density archival technology for the digital age.