2025/07/20 by Sayat, Mikhael T., Lee, Trevor R., Negi, Suchit +6
#FOS: Physical sciences #Quantum Physics (quant-ph)
paper · doi:10.48550/arxiv.2507.15051
In the endeavour of developing quantum memories, Er3+:CaWO4 has emerged as a promising rare-earth ion-doped (REID) crystal platform due to its long optical coherence times and compatibility with the 1550 nm telecommunications band. This work investigates the effects of polarisation and temperature on the absorption strength, central wavelength, and linewidth of the Z1→ Y1 and Z1→ Y2 optical transitions, with light incident along the crystal a and c axes. It is found that the Z1→ Y1 transition at 1532.6 nm with the incident laser along the c-axis at cryogenic temperatures (∼3 K) is particularly favourable. The transition exhibits a stable central wavelength, narrower linewidth, polarisation independence, larger absorption cross-section, and lies within the C-band -- attributes that make it highly suitable for quantum memory applications.