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Great enhancement of Faraday effect by Pr doping terbium gallium garnet, a highly transparent VI-IR Faraday rotator
Materials Letters 145 (2015) 171–173
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Great enhancement of Faraday effect by Pr doping terbium gallium garnet, a highly transparent VI-IR Faraday rotator Zhe Chen n, Yin Hang, Lei Yang, Jun Wang, Xiangyong Wang, Peixiong Zhang, Jiaqi Hong, Chunjun Shi, Yaqi Wang Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, No. 390, Qinghe Road, Jiading District, Shanghai 201800, China
art ic l e i nf o
a b s t r a c t
Article history: Received 31 October 2014 Accepted 23 January 2015 Available online 2 February 2015
A highly transparent (Tb(1 x)Prx)3Ga5O12 (TPGG) single crystal was grown by the Czochralski (Cz) method. The grown crystal was characterized by x-ray diffraction analysis which showed the crystal belongs to cubic structure with high crystallinity. The optical and magneto-optical properties of TPGG are analyzed in detailed and its figure of merit as Faraday rotator has been determined at room temperature. The Verdet constant of TPGG at 632.8 nm was 182.43 rad m 1 T 1, which is 36.14% larger than that of terbium gallium garnet (TGG). The thermal conductivity and laser induced damage threshold (LIDT) of the TPGG were also measured. Overall, the TPGG single crystal studied here exhibits superior properties than the commercial TGG so far, therefore it has potential to cover the increasing demand for new and improved Faraday rotators in the VI-IR region. & 2015 Published by Elsevier B.V.
Keywords: Crystal growth Crystal structure Optical materials and properties Magnetic materials
1. Introduction The Faraday rotator (FR) is one of the most important magnetooptical materials due to its broad applications field, such as optical isolator (OIs), electrical current sensors, optical modulators, and so on [1,2]. A FR can be a single crystal, a glass, a ceramic or even a gas, among which the single crystal presents incomparable thermal and magneto-optical properties because of its high thermal conductivity, size scalability, high LIDT [3,4]. With the rapid advance in high-energy and high-average-power laser systems, the research and application of OIs that can be used in VI-IR region become more and more important and the demand for optical Faraday devices at wavelengths of 400–1100 nm is increasing rapidly [5,6]. However, yttrium iron garnet (YIG) cannot be used at shorter wavelengths (o1100 nm) due to its poor transparency [7,8]. Although terbium aluminum garnet (Tb3Al5O12 (TAG)) and TGG single crystals show excellent magneto-optical properties, the former is extremely difficult to grow large size single crystal for its incongruent melting nature and the latter has a comparative low Verdet constant ( 134.0 rad m 1 T 1) [9,10], so there is an urgent hope to find magneto-optical materials with large Verdet constant that can be effective in size-reduction of FR. Larger Verdet constant means even a smaller size of crystal (length o10 mm) can obtain a
n
Corresponding author. Tel.: þ 86 21 69918625. E-mail address: [email protected] (Z. Chen).
http://dx.doi.org/10.1016/j.matlet.2015.01.108 0167-577X/& 2015 Published by Elsevier B.V.
sufficient 451 Faraday rotational angle to avoid laser-induced damage under high-energy pulse operation and the thermal birefringence effect [11], thus improves the stability of FR which is important in the laser systems. The main properties of TGG are a high transparency in the near IR and a congruently melting type material. Thus, the TGG single crystal having a bulk size can be easily produced by the known Cz process [12]. The reports on Fluoride single crystals with high concentration of efficient paramagnetic RE ions (CeF3, PrF3, TbF3, DyF3, HoF3, ErF3) in UV-VI region were worth mentioning due to their comparatively large Verdet constants at room temperature [13,14]. Some magneto-optical glass doping more than one paramagnetic RE ions showed excellent Faraday effect [15,16]. Ce3 þ – Bi3 þ co-doped strongly enhanced the Faraday rotation of the YIF epitaxial films [17,18]. Also for the single crystal, Tb3[Sc1.95Lu0.05] (Al3)O12 garnet (TSLAG) crystal presented superior magnetooptical properties to TAG crystal by doping the Sc3 þ , Lu3 þ ions [19]. All the above showed that the quantum based super exchange interaction between Tb3 þ and other paramagnetic RE ions or two paramagnetic RE ions might occur [17], which can enhance the Faraday effect of the materials. In this letter, we focus on the analysis of terbium type paramagnetic garnet single crystal and we hope to provide a terbium type paramagnetic garnet single crystal which the Faraday effect is large, the light transmission factor is high and the Verdet constant is enhanced and to provide a magneto-optical device using the terbium type paramagnetic single crystal. Among
172
Z. Chen et al. / Materials Letters 145 (2015) 171–173
Fig. 1. X-ray powder diffraction patterns of the powder specimen (a) and the rocking curve for the TPGG crystal (b). The inset shows the bulk TPGG crystals with dimension of Φ25 mm 50 mm and samples of double-side polished to the same size of Φ8 mm 5 mm.
Fig. 2. The transmission spectra of TPGG and TGG crystals (a) and the Verdet constant dispersion of TPGG in comparison with that of TGG (b).
the paramagnetic ions, Pr3 þ showed excellent Faraday effect and its ion radius is similar to that of Tb3 þ , so a Pr3 þ doped terbium type garnet crystal with larger Verdet constant is possibly achievable.
was measured at room temperature with the FR test apparatus by the magneto-optic modulated double-frequency technique [11].
3. Result and discussion
2. Material and methods For the polycrystalline material preparation, Tb4O7, Pr6O11 and Ga2O3 (99.999%) were mixed according to the corresponding nominal cationic ratios. Then pressed into tablets and were sintered at 1400 1C for 20 h in air. It was grown in the (1 1 1) orientation at a pulling rate of 2.0 mm h 1 and a rotating rate of 10–15 rpm by the Cz method. The XRD was carried out by the Ultima IV (Rigaku, Japan) and the rocking curve for the crystal was measured by the PANalytical Empyrean XRD apparatus. The transmission spectrum was measured using a Perkin-Elmer Lambda 900 UV–vis–NIR spectrophotometer (Japan). The element analysis results of the crystal were measured by the ICP-AES method. The refractive index was determined using a glass prism and the total reflection method at selected wavelengths: 632 nm, 1064 nm and the nonlinear index n2 at 1064 nm of the samples using the z-scan measurement technique. The thermal conductivity of the sample with the best quality was measured by the well-known flash method on a Xenon Flash Apparatus (LFA447/1 NanoFlashR300, Netzsch, Germany). The bulk laser damage threshold was measured using common testing conditions (Nd:YAG laser system, 1064 nm wavelength, 12 ns pulse duration,1-on-1 test). The specific Faraday rotation of single crystals
The as-grown (Tb(1 x)Prx)3Ga5O12 single crystal obtained by the Cz method was ground into powder and its X-ray powder diffraction pattern was shown in Fig. 1(a). Compared with the JCPDS standard card, the XRD powder diffraction pattern of TPGG crystal is agree well with the standard patterns of TGG crystal (JCPDS 88–0575) without any impurities peaks. The crystal TPGG belongs to the cubic system and the unit-cell parameters are a¼b¼c¼1.2389 nm, smaller that of TPGG (a¼b¼c¼1.2355 nm). It can be explained by the reason that the radius of Pr3 þ is larger than the radius of Tb3 þ . The full width at half-maximum of the rocking curve for the crystal presented in Fig. 1(b) is about 25 arcs which shows the high crystallinity of the crystal. The inset of Fig. 1(b) shows the bulk TPGG crystals with dimension of Φ25 mm 50 mm and samples of double-side polished to the same size of Φ8 mm 5 mm. The element analysis results shows that the crystal grown from the melt can be expressed as Tb2.92Pr0.08Ga5O12 according to the measured molar ratio. The optical transmittance spectra of TGG and TPGG are shown in Fig. 2(a). The absorption peaks of S1, S3, S4 at 451, 478, 492 nm correspond to the emission of Pr3 þ :3H4-3P(0 1 2); S2 at 484 nm is due to the Tb3 þ :7F6-5D4. Another two strong peaks (S5, S6) center around 598 nm corresponding with the Pr3 þ :3H4-1D2. In the working wavelength around 532, 632.8, 1064 nm, TPGG has good optical transparency which can reach 80% upwards. The
Z. Chen et al. / Materials Letters 145 (2015) 171–173
173
Fig. 3. The transmission spectra of TPGG and TGG crystals (a) and the Verdet constant dispersion of TPGG in comparison with that of TGG (b).
Table 1 Comparison between TPGG and TGG of the main important parameters. Crystal
Tb2.92Pr0.08Ga5O12
Tb3Ga5O12
Wavelength (nm) Refractive index Verdet constant (rad m 1 T 1) Nonlinear index n2 (10 15 cm2 W 1)
632 1.94 182.43 –
632 1.96 134.00 –
1064 1.92 62.78 2.83
1064 1.95 39.30 1.76
- Not measured.
measured Verdet constants at wavelength of 532, 633, 830, 1064 nm are 264.50, 182.43, 105.62, 62.78 rad m 1 T 1, which 2 2 were fitted according to the V ¼ ðE=ðλ λ0 ÞÞ [8], shown in Fig. 2 (b). Therefore, the high transmittance and Verdet constants indicates that the as-grown single crystal in our work is suitable for application of apparatus used in the working wavelength around 532, 632.8, 1064 nm and 600–1000 nm. In order to check the potential usage of TPGG in high power laser system, thermal conductivity (Fig. 3(a)) and LIDT of the crystal have been measured. The thermal conductivity of TPGG at room temperature was 7.2 W m 1 K 1, almost same as the high-quality pure TGG (7.4 W m 1 K 1), dropping to the 4.2 W m 1 K 1 at 500 1C. The probability of damage is plotted as a function of the test fluence. Linear extrapolation of the damage probability data to zero damage probability yields the threshold energy as shown in Fig. 3(b). The LIDT of measured was about 10.1 J cm 2. These results further confirm the high quality of the TPGG crystal and its further application in the high power Faraday devices. Absorption loss is an important parameter of magneto-optical properties. The Faraday rotation of TPGG in the wavelength of 632.8 nm is 125.491 cm 1, while the optical absorption coefficient is 0.50 cm 1. The magneto-optical figure of merit of the crystal is calculated to be 58.321 dB 1, which is 44.73% larger than that of TGG. Other main important parameters are also given in Table 1. Therefore, TPGG is an attractive candidate to substitute TGG crystals used in Faraday isolators for optical communication systems in wavelengths of 500–1100 nm (besides around 598 nm). 4. Conclusion (Tb(1 x)Prx)3Ga5O12(TPGG) single crystal was grown by the Cz method. The magneto-optical figure of merit of the TPGG crystal was about 44.73% larger than that of TGG. The doping of Pr3 þ may cause super-exchange interaction, which produces a further splitting of
crystal. The transition probability from the base 4f to 5d energy level contributing differently to the polarization light leads to the huge Faraday effect. A theoretical interpretation of the increase in Faraday rotation will require further experiments concerning detailed crystal field analysis and quantum based super-exchange interaction. Although the concentration of Pr3 þ is still small, the increase of 36.14% in the Verdet constant is very significant, giving a huge expectation of getting a more excellent magneto-optical material from (Tb(1 x)Prx)3Ga5O12 by adjusting the X value. TPGG single crystal has great potential to replace the commercial TGG crystals for magneto-optical devices in the visible and near-infrared regions.
Acknowledgment This work was supported by Nature Science Foundation of China (no. 51472257).
References [1] Kagan MA, Khazanov. EA. Appl Opt 2004;43:6030. [2] Kaminskii AA, Eichler HJ, Reiche P, Uecker. R. Laser Phys Lett 2005;2:489. [3] Mansell JD, Hennawi J, Gustafson EK, Fejer MM, Byer RL, et al. Appl Opt 2001;40:366. [4] G Mueller, RS Amin, D Guagliardo, D McFeron, R Lundock, et al. Classical Quant Grav 2002;19;1793. [5] Banerjee S, Ertel K, Mason PD, Phillips PJ, Siebold M, et al. Opt Lett 2012;37:2175. [6] Yasuhara R, Kawashima T, Sekine T, Kurita T, Ikegawa T, et al. Opt Lett 2008;33:1711. [7] Ghosh S, Keyvaninia S, Roy WV, Mizumoto T, Roelkens G, et al. Opt Lett 2013;38:965. [8] Víllora EG, Molina P, Nakamura M, Shimamura K, Hatanaka T, et al. Appl Phys Lett 2011;99:011111. [9] Kaminskii AA, Eichler HJ, Reiche P, Uecker. R. Laser Phys Lett 2005;2:489. [10] Zheleznov D, Starobor A, Palashov O, Lin H, Zhou. S. Opt Lett 2014;39:2183. [11] Yoshida H, Tsubakimoto K, Fujimoto Y, Mikami K, Fujita H, et al. Opt Express 2011;19:15181. [12] Yasuhara R, Furuse. H. Opt Lett 2013;38:1751. [13] Vasyliev V, Villora EG, Nakamura M, Sugahara Y, Shimamura K. Opt Express 2012;20:14460. [14] Vasyliev V, Molina P, Nakamura M, Víllora EG, Shimamura. K. Opt Mater 2011;33:1710. [15] Tanaka K, Tatehata N, Fujita K, Hirao K, Soga. N. J. Phys D: Appl Phys 1998;31:2622. [16] Hayakawa T, Nogami M, Nishi N, Sawanobori. N. Chem Mater 2002;14:3223. [17] Sekhar MC, Hwang J, Ferrera M, Linzon Y, Razzari L, et al. Appl Phys Lett 2009;94:181916. [18] Kahl S, Khartsev SI, Grishin AM, Kawano K, Konget G, et al. J Appl Phys 2002;91:9556. [19] Shimamura K, Kito T, Castel E, Latynina A, Molina P, et al. Cryst Growth Des 2010;10:3466.
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Great enhancement of Faraday effect by Pr doping terbium gallium garnet, a highly transparent VI-IR Faraday rotator Zhe Chen n, Yin Hang, Lei Yang, Jun Wang, Xiangyong Wang, Peixiong Zhang, Jiaqi Hong, Chunjun Shi, Yaqi Wang Key Laboratory of Materials for High Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, No. 390, Qinghe Road, Jiading District, Shanghai 201800, China
art ic l e i nf o
a b s t r a c t
Article history: Received 31 October 2014 Accepted 23 January 2015 Available online 2 February 2015
A highly transparent (Tb(1 x)Prx)3Ga5O12 (TPGG) single crystal was grown by the Czochralski (Cz) method. The grown crystal was characterized by x-ray diffraction analysis which showed the crystal belongs to cubic structure with high crystallinity. The optical and magneto-optical properties of TPGG are analyzed in detailed and its figure of merit as Faraday rotator has been determined at room temperature. The Verdet constant of TPGG at 632.8 nm was 182.43 rad m 1 T 1, which is 36.14% larger than that of terbium gallium garnet (TGG). The thermal conductivity and laser induced damage threshold (LIDT) of the TPGG were also measured. Overall, the TPGG single crystal studied here exhibits superior properties than the commercial TGG so far, therefore it has potential to cover the increasing demand for new and improved Faraday rotators in the VI-IR region. & 2015 Published by Elsevier B.V.
Keywords: Crystal growth Crystal structure Optical materials and properties Magnetic materials
1. Introduction The Faraday rotator (FR) is one of the most important magnetooptical materials due to its broad applications field, such as optical isolator (OIs), electrical current sensors, optical modulators, and so on [1,2]. A FR can be a single crystal, a glass, a ceramic or even a gas, among which the single crystal presents incomparable thermal and magneto-optical properties because of its high thermal conductivity, size scalability, high LIDT [3,4]. With the rapid advance in high-energy and high-average-power laser systems, the research and application of OIs that can be used in VI-IR region become more and more important and the demand for optical Faraday devices at wavelengths of 400–1100 nm is increasing rapidly [5,6]. However, yttrium iron garnet (YIG) cannot be used at shorter wavelengths (o1100 nm) due to its poor transparency [7,8]. Although terbium aluminum garnet (Tb3Al5O12 (TAG)) and TGG single crystals show excellent magneto-optical properties, the former is extremely difficult to grow large size single crystal for its incongruent melting nature and the latter has a comparative low Verdet constant ( 134.0 rad m 1 T 1) [9,10], so there is an urgent hope to find magneto-optical materials with large Verdet constant that can be effective in size-reduction of FR. Larger Verdet constant means even a smaller size of crystal (length o10 mm) can obtain a
n
Corresponding author. Tel.: þ 86 21 69918625. E-mail address: [email protected] (Z. Chen).
http://dx.doi.org/10.1016/j.matlet.2015.01.108 0167-577X/& 2015 Published by Elsevier B.V.
sufficient 451 Faraday rotational angle to avoid laser-induced damage under high-energy pulse operation and the thermal birefringence effect [11], thus improves the stability of FR which is important in the laser systems. The main properties of TGG are a high transparency in the near IR and a congruently melting type material. Thus, the TGG single crystal having a bulk size can be easily produced by the known Cz process [12]. The reports on Fluoride single crystals with high concentration of efficient paramagnetic RE ions (CeF3, PrF3, TbF3, DyF3, HoF3, ErF3) in UV-VI region were worth mentioning due to their comparatively large Verdet constants at room temperature [13,14]. Some magneto-optical glass doping more than one paramagnetic RE ions showed excellent Faraday effect [15,16]. Ce3 þ – Bi3 þ co-doped strongly enhanced the Faraday rotation of the YIF epitaxial films [17,18]. Also for the single crystal, Tb3[Sc1.95Lu0.05] (Al3)O12 garnet (TSLAG) crystal presented superior magnetooptical properties to TAG crystal by doping the Sc3 þ , Lu3 þ ions [19]. All the above showed that the quantum based super exchange interaction between Tb3 þ and other paramagnetic RE ions or two paramagnetic RE ions might occur [17], which can enhance the Faraday effect of the materials. In this letter, we focus on the analysis of terbium type paramagnetic garnet single crystal and we hope to provide a terbium type paramagnetic garnet single crystal which the Faraday effect is large, the light transmission factor is high and the Verdet constant is enhanced and to provide a magneto-optical device using the terbium type paramagnetic single crystal. Among
172
Z. Chen et al. / Materials Letters 145 (2015) 171–173
Fig. 1. X-ray powder diffraction patterns of the powder specimen (a) and the rocking curve for the TPGG crystal (b). The inset shows the bulk TPGG crystals with dimension of Φ25 mm 50 mm and samples of double-side polished to the same size of Φ8 mm 5 mm.
Fig. 2. The transmission spectra of TPGG and TGG crystals (a) and the Verdet constant dispersion of TPGG in comparison with that of TGG (b).
the paramagnetic ions, Pr3 þ showed excellent Faraday effect and its ion radius is similar to that of Tb3 þ , so a Pr3 þ doped terbium type garnet crystal with larger Verdet constant is possibly achievable.
was measured at room temperature with the FR test apparatus by the magneto-optic modulated double-frequency technique [11].
3. Result and discussion
2. Material and methods For the polycrystalline material preparation, Tb4O7, Pr6O11 and Ga2O3 (99.999%) were mixed according to the corresponding nominal cationic ratios. Then pressed into tablets and were sintered at 1400 1C for 20 h in air. It was grown in the (1 1 1) orientation at a pulling rate of 2.0 mm h 1 and a rotating rate of 10–15 rpm by the Cz method. The XRD was carried out by the Ultima IV (Rigaku, Japan) and the rocking curve for the crystal was measured by the PANalytical Empyrean XRD apparatus. The transmission spectrum was measured using a Perkin-Elmer Lambda 900 UV–vis–NIR spectrophotometer (Japan). The element analysis results of the crystal were measured by the ICP-AES method. The refractive index was determined using a glass prism and the total reflection method at selected wavelengths: 632 nm, 1064 nm and the nonlinear index n2 at 1064 nm of the samples using the z-scan measurement technique. The thermal conductivity of the sample with the best quality was measured by the well-known flash method on a Xenon Flash Apparatus (LFA447/1 NanoFlashR300, Netzsch, Germany). The bulk laser damage threshold was measured using common testing conditions (Nd:YAG laser system, 1064 nm wavelength, 12 ns pulse duration,1-on-1 test). The specific Faraday rotation of single crystals
The as-grown (Tb(1 x)Prx)3Ga5O12 single crystal obtained by the Cz method was ground into powder and its X-ray powder diffraction pattern was shown in Fig. 1(a). Compared with the JCPDS standard card, the XRD powder diffraction pattern of TPGG crystal is agree well with the standard patterns of TGG crystal (JCPDS 88–0575) without any impurities peaks. The crystal TPGG belongs to the cubic system and the unit-cell parameters are a¼b¼c¼1.2389 nm, smaller that of TPGG (a¼b¼c¼1.2355 nm). It can be explained by the reason that the radius of Pr3 þ is larger than the radius of Tb3 þ . The full width at half-maximum of the rocking curve for the crystal presented in Fig. 1(b) is about 25 arcs which shows the high crystallinity of the crystal. The inset of Fig. 1(b) shows the bulk TPGG crystals with dimension of Φ25 mm 50 mm and samples of double-side polished to the same size of Φ8 mm 5 mm. The element analysis results shows that the crystal grown from the melt can be expressed as Tb2.92Pr0.08Ga5O12 according to the measured molar ratio. The optical transmittance spectra of TGG and TPGG are shown in Fig. 2(a). The absorption peaks of S1, S3, S4 at 451, 478, 492 nm correspond to the emission of Pr3 þ :3H4-3P(0 1 2); S2 at 484 nm is due to the Tb3 þ :7F6-5D4. Another two strong peaks (S5, S6) center around 598 nm corresponding with the Pr3 þ :3H4-1D2. In the working wavelength around 532, 632.8, 1064 nm, TPGG has good optical transparency which can reach 80% upwards. The
Z. Chen et al. / Materials Letters 145 (2015) 171–173
173
Fig. 3. The transmission spectra of TPGG and TGG crystals (a) and the Verdet constant dispersion of TPGG in comparison with that of TGG (b).
Table 1 Comparison between TPGG and TGG of the main important parameters. Crystal
Tb2.92Pr0.08Ga5O12
Tb3Ga5O12
Wavelength (nm) Refractive index Verdet constant (rad m 1 T 1) Nonlinear index n2 (10 15 cm2 W 1)
632 1.94 182.43 –
632 1.96 134.00 –
1064 1.92 62.78 2.83
1064 1.95 39.30 1.76
- Not measured.
measured Verdet constants at wavelength of 532, 633, 830, 1064 nm are 264.50, 182.43, 105.62, 62.78 rad m 1 T 1, which 2 2 were fitted according to the V ¼ ðE=ðλ λ0 ÞÞ [8], shown in Fig. 2 (b). Therefore, the high transmittance and Verdet constants indicates that the as-grown single crystal in our work is suitable for application of apparatus used in the working wavelength around 532, 632.8, 1064 nm and 600–1000 nm. In order to check the potential usage of TPGG in high power laser system, thermal conductivity (Fig. 3(a)) and LIDT of the crystal have been measured. The thermal conductivity of TPGG at room temperature was 7.2 W m 1 K 1, almost same as the high-quality pure TGG (7.4 W m 1 K 1), dropping to the 4.2 W m 1 K 1 at 500 1C. The probability of damage is plotted as a function of the test fluence. Linear extrapolation of the damage probability data to zero damage probability yields the threshold energy as shown in Fig. 3(b). The LIDT of measured was about 10.1 J cm 2. These results further confirm the high quality of the TPGG crystal and its further application in the high power Faraday devices. Absorption loss is an important parameter of magneto-optical properties. The Faraday rotation of TPGG in the wavelength of 632.8 nm is 125.491 cm 1, while the optical absorption coefficient is 0.50 cm 1. The magneto-optical figure of merit of the crystal is calculated to be 58.321 dB 1, which is 44.73% larger than that of TGG. Other main important parameters are also given in Table 1. Therefore, TPGG is an attractive candidate to substitute TGG crystals used in Faraday isolators for optical communication systems in wavelengths of 500–1100 nm (besides around 598 nm). 4. Conclusion (Tb(1 x)Prx)3Ga5O12(TPGG) single crystal was grown by the Cz method. The magneto-optical figure of merit of the TPGG crystal was about 44.73% larger than that of TGG. The doping of Pr3 þ may cause super-exchange interaction, which produces a further splitting of
crystal. The transition probability from the base 4f to 5d energy level contributing differently to the polarization light leads to the huge Faraday effect. A theoretical interpretation of the increase in Faraday rotation will require further experiments concerning detailed crystal field analysis and quantum based super-exchange interaction. Although the concentration of Pr3 þ is still small, the increase of 36.14% in the Verdet constant is very significant, giving a huge expectation of getting a more excellent magneto-optical material from (Tb(1 x)Prx)3Ga5O12 by adjusting the X value. TPGG single crystal has great potential to replace the commercial TGG crystals for magneto-optical devices in the visible and near-infrared regions.
Acknowledgment This work was supported by Nature Science Foundation of China (no. 51472257).
References [1] Kagan MA, Khazanov. EA. Appl Opt 2004;43:6030. [2] Kaminskii AA, Eichler HJ, Reiche P, Uecker. R. Laser Phys Lett 2005;2:489. [3] Mansell JD, Hennawi J, Gustafson EK, Fejer MM, Byer RL, et al. Appl Opt 2001;40:366. [4] G Mueller, RS Amin, D Guagliardo, D McFeron, R Lundock, et al. Classical Quant Grav 2002;19;1793. [5] Banerjee S, Ertel K, Mason PD, Phillips PJ, Siebold M, et al. Opt Lett 2012;37:2175. [6] Yasuhara R, Kawashima T, Sekine T, Kurita T, Ikegawa T, et al. Opt Lett 2008;33:1711. [7] Ghosh S, Keyvaninia S, Roy WV, Mizumoto T, Roelkens G, et al. Opt Lett 2013;38:965. [8] Víllora EG, Molina P, Nakamura M, Shimamura K, Hatanaka T, et al. Appl Phys Lett 2011;99:011111. [9] Kaminskii AA, Eichler HJ, Reiche P, Uecker. R. Laser Phys Lett 2005;2:489. [10] Zheleznov D, Starobor A, Palashov O, Lin H, Zhou. S. Opt Lett 2014;39:2183. [11] Yoshida H, Tsubakimoto K, Fujimoto Y, Mikami K, Fujita H, et al. Opt Express 2011;19:15181. [12] Yasuhara R, Furuse. H. Opt Lett 2013;38:1751. [13] Vasyliev V, Villora EG, Nakamura M, Sugahara Y, Shimamura K. Opt Express 2012;20:14460. [14] Vasyliev V, Molina P, Nakamura M, Víllora EG, Shimamura. K. Opt Mater 2011;33:1710. [15] Tanaka K, Tatehata N, Fujita K, Hirao K, Soga. N. J. Phys D: Appl Phys 1998;31:2622. [16] Hayakawa T, Nogami M, Nishi N, Sawanobori. N. Chem Mater 2002;14:3223. [17] Sekhar MC, Hwang J, Ferrera M, Linzon Y, Razzari L, et al. Appl Phys Lett 2009;94:181916. [18] Kahl S, Khartsev SI, Grishin AM, Kawano K, Konget G, et al. J Appl Phys 2002;91:9556. [19] Shimamura K, Kito T, Castel E, Latynina A, Molina P, et al. Cryst Growth Des 2010;10:3466.