Bi$_{3}$ Fe$_{4}$Ga$_{1}$O $_{12}$ Garnet Properties and Its Application to Ultrafast Switching in the Visible Spectrum

We have synthesized Bi
₃
Fe
₄
Ga
₁
O
₁₂
(BIGG) films on Gd
₃
Ga
₅
O
₁₂
and Gd
₃
(ScGa)
₅
O
₁₂
substrates by a pulsed laser deposition technique. X-ray diffraction and rocking curve analyses confirm the epitaxial quality of the films with a lattice constant close to 12.61 plusmn 0.01 Aring. Compared with that of a bismuth iron garnet Bi
₃
Fe
₅
O
₁₂
(BIG) film, the bandwidth of the BIGG transmittance (T) spectrum is extended and its left edge shifted down in wavelength by approximately 50 nm. This enables its Faraday rotation and switching speed to be tested at a wavelength of 532 nm. While BIGG film has a Faraday rotation angle slightly less than that of BIG film, its magnetooptical figure of merit, 2|thetas
_F
d|/-ln(T%), is greatly improved to a typical value ~1.8 times larger than that of the BIG film. Further, the high-speed pulse response time of the BIGG film reaches 2.4 ns with a 1 mm aperture size at the wavelength of 532 nm.