Ferroelectric crystals with giant electro-optic property enabling ultracompact Q-switches

Abstract

Relaxor-lead titanate (PbTiO 3 ) crystals, which exhibit extremely high piezoelectricity, are believed to possess high electro-optic (EO) coefficients. However, the optical transparency of relaxor-PbTiO 3 crystals is severely reduced as a result of light scattering and reflection by domain walls, limiting electro-optic applications. Through synergistic design of a ferroelectric phase, crystal orientation, and poling technique, we successfully removed all light-scattering domain walls and achieved an extremely high transmittance of 99.6% in antireflection film–coated crystals, with an ultrahigh EO coefficient r 33 of 900 picometers per volt (pm V −1 ), >30 times as high as that of conventionally used EO crystals. Using these crystals, we fabricated ultracompact EO Q-switches that require very low driving voltages, with superior performance to that of commercial Q-switches. Development of these materials is important for the portability and low driving voltage of EO devices.

Sm-Doped PIN-PMN-PT Transparent Ceramics with High Curie Temperature, Good Piezoelectricity, and Excellent Electro-Optical Properties

“…Some ferroelectric materials probably have a high electro-optical coefficient, such as (Sr, Ba)Nb 2 O 6 crystals (r 33 ∼ 235 pm/ V), 57 but their good performance is a consequence of ferroelectric phase transition temperature approaching room temperature, which seriously restricts its working temperature extent. Moreover, the electro-optical coefficients r c of Smdoped 24PIN-42PMN-34PT ceramics are superior to those of formerly recommended relaxor ferroelectric crystals, including [011]-PIN-PMN-32PT 16 and [110]-PMN-28PT. 2 It can be attributed to the rare earth element doping and the formation of MPBs.…”

“…It can be obtained that the 1.0 mol % Sm-doped 24PIN-42PMN-34PT transparent ceramic has an optimum comprehensive performance including an excellent electro-optical coefficient r c of 814 pm/V and high Curie temperature T C of 179 °C. The electro-optical coefficient r c of 1.0 mol % Sm-PIN-PMN-PT ceramic is ∼40 times as large as those of LN (LiNbO 3 ) (∼21 pm/V) and DKDP (KD 2 PO 4 ) (∼24 pm/V) electro-optical crystals, 16 demonstrating promising applications in portable electro-optical devices with low operating voltages. Some ferroelectric materials probably have a high electro-optical coefficient, such as (Sr, Ba)Nb 2 O 6 crystals (r 33 ∼ 235 pm/ V), 57 but their good performance is a consequence of ferroelectric phase transition temperature approaching room temperature, which seriously restricts its working temperature extent.…”

“…Figure 4b displays the variation of phase shift with the electric field, where a typical linear relationship can be observed. This indicates that Sm-24PIN-42PMN-34PT transparent piezoelectric ceramics have the linear electro-optic effect (Pockels effect), 16 which differs from the quadratic electro-optic effect of PMN-PT transparent ceramics. 22 Linear electro-optic effect of Sm-PIN-PMN-PT ceramics is mainly caused by its low symmetry of crystal structure, as shown in Figure S1.…”

“…In 2022, Li and coworkers successfully fabricated Pb(In 1/2 Nb 1/2 )O 3 -Pb-(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 (PIN-PMN-PT) crystals with an ultra-high transmittance of 70% and high Curie point of 180 °C, while the piezoelectric properties were relatively low. 16 In addition, Cui et al obtained PIN-PMN-PT crystals with giant piezoelectric properties of 1400 pC/N and a high Curie point of 200 °C, while the crystals are opaque. 17 Thus, the PIN-PMN-PT system is possible to obtain high piezoelectric properties, high Curie temperature, and high transmittance simultaneously.…”

“…Therefore, obtaining transparent ferroelectrics with both high piezoelectric effect and high Curie temperature becomes another difficult task. In 2022, Li and co-workers successfully fabricated Pb­(In 1/2 Nb 1/2 )­O 3 -Pb­(Mg 1/3 Nb 2/3 )­O 3 -PbTiO 3 (PIN-PMN-PT) crystals with an ultra-high transmittance of 70% and high Curie point of 180 °C, while the piezoelectric properties were relatively low . In addition, Cui et al obtained PIN-PMN-PT crystals with giant piezoelectric properties of 1400 pC/N and a high Curie point of 200 °C, while the crystals are opaque .…”