Observation and investigation of narrow optical transitions of¹⁶⁷Er³⁺ions in femtosecond laser printed waveguides in⁷LiYF₄crystal

Abstract

We produced optical waveguides in the 167 Er 3+ : 7 LiYF 4 crystal with diameters ranging from 30 to 100 μm by using the depressed-cladding approach with femtosecond laser. Stationary and coherent spectroscopy was performed on the 809 nm optical transitions between the hyperfine sublevels of 4 I 15/2 and 4 I 9/2 multiplets of 167 Er 3+ ions both inside and outside of waveguides. It was found that the spectra of 167 Er 3+ were slightly broadened and shifted inside the waveguides compared to the bulk crystal spectra. We managed to observe a two-pulse photon echo on this transition and determined phase relaxation times for each waveguide. The experimental results show that the created crystal waveguides doped by rare-earth ions can be used in optical quantum memory and integrated quantum schemes.

A Mechanistic Understanding of Nonclassical Crystal Growth in Hydrothermally Synthesized Sodium Yttrium Fluoride Nanowires

“…19 Lanthanide ions doped within fluoride crystals are also under active investigation for applications such as long-lived optical quantum memories. 20 One important example of these materials is sodium yttrium fluoride (NaYF 4 ), which has been studied not only for its optical and electronic prop-erties, [21][22][23][24] but also for its morphological and crystallographic microstructure. 4,25,26 Traditionally, bulk single crystals of NaYF 4 have been grown using high-temperature Czochralski or Bridgman methods, [26][27][28] but this method has shown difficulties in obtaining single crystals of the hexagonal phase due to large anisotropic thermal expansion coefficients.…”

A Mechanistic Understanding of Non-Classical Crystal Growth in Hydrothermally Synthesized Sodium Yttrium Fluoride Nanowires

“…100 Furthermore, a thorough understanding of the synthesis mechanism based on particle interactions can inform future experiments meant to direct the morphology of β-NaYF 4 particles, and could even help to design a predictive model to control the morphology and size of NaYF 4 materials. 20…”

CNOT gate on reverse photon modes in a ring cavity

“…In addition to this approach we suggest femtosecond laser written waveguide in fused silica plate [26,27]. Robust construction of this device is shown in Fig.…”