Optical bistability in Er-Yb codoped phosphate glass microspheres at room temperature

Abstract

Type of publicationArticle ( We experimentally demonstrate optical bistability in Er 3+ -Yb 3+ phosphate glass microspheres at 295 K. Bistability is associated with both Er 3+ fluorescence and lasing behavior, and chromatic switching. The chromatic switching results from an intrinsic mechanism exploiting the thermal coupling of closely spaced energy levels, and occurs simultaneously with the intensity switching. A contrast ratio of 2.8 has been obtained for chromatic switching. The intensity switching shows ratios of 21 for 520 nm and 11 for 660 nm fluorescence emissions, and 11 for IR lasing at 1.5 m. Concurrent with these observations, we investigate a temperature-dependent absorption of pump power, which exhibits bistable behavior. The influences of the host matrix on lasing and fluorescence mechanisms are highlighted.

Ultralow threshold green lasing and optical bistability in ZBNA (ZrF4–BaF2–NaF–AlF3) microspheres

“…In earlier work, 13 optical bistability over multiple wavelengths in an IOG2 phosphate glass microsphere was demonstrated and attributed to a thermo-optical effect. Phonon transitions excited after optical pumping around 978 nm generate heat in the glass.…”

“…Optical bistability of stimulated emission lines 12 in Sm 3+ doped glass microspheres was observed in 2001 and, subsequently, in Er 3+ / Yb 3+ codoped phosphate glass ͑IOG2͒ microcavities. 13 In the latter work, the effect is due to thermo-optical heating of the microsphere resulting in wavelength shifting of the microsphere's optical modes. Here, the emission characteristics of Er 3+ doped ZBNA microspheres are investigated and an ultralow green upconversion lasing threshold of ϳ3 W is demonstrated.…”

Thermo-optical tuning of whispering gallery modes in erbium doped microspheres

“…The cavity/pump resonances and the shifting WGMs are the cause of optical bistability in glass microspheres. [26][27][28] The chance for occurrence of a pump/cavity resonance maybe reduced by using a broad amplified spontaneous emission pump source with no sharp spectral features; however, a higher pump power may then be needed to achieve a tuning range larger than 300 GHz.…”

Spectroscopy, Manipulation and Trapping of Neutral Atoms, Molecules, and Other Particles Using Optical Nanofibers: A Review

“…The development of optical cavities has been of great interest in research for many years due to the significant enhancement effects and detection sensitivity offered by these devices [103]. With improved fabrication techniques various types of optical microcavities have been investigated [104][105][106][107][108][109]. Such microcavities have proven to be a productive platform for experiments with such effects as strong coupling [110] and the Purcell effect [111] being demonstrated.…”