Refractive index database

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Optical constants of Bi4Ti3O12 (Bismuth titanate, BTO)
Simon et al. 1997: n(a); 0.45–0.70 µm

Wavelength: µm

Complex refractive index (n+ik)[ i ]

n   k   LogX   LogY   eV

Derived optical constants

Dispersion formula [ i ]



Polarization parallel to a-axis. 21 °C.


M. Simon et al.. Refractive indices of photorefractive bismuth titanate, barium-calcium titanate, bismuth germanium oxide, and lead germanate, Phys. Stat. Sol. 159, 559-562 (1997)


[Expressions for n]   [CSV - comma separated]   [TXT - tab separated]   [Full database record]


Bismuth titanate, Bi4Ti3O12 (BTO)

Bi4Ti3O12, commonly referred to as bismuth titanate (BTO), is a ferroelectric material that has attracted considerable attention for its diverse range of applications, from non-volatile memories to piezoelectric devices. In optics, BTO has been investigated as a nonlinear optical material and as a candidate for photonic applications where electric field-controlled refractive index changes are advantageous. One of its most notable properties is its high Curie temperature, which makes it stable over a wide temperature range. Additionally, the material has a high spontaneous polarization and a large electro-optic coefficient, making it suitable for modulators and switches. BTO can be synthesized using various methods such as sol-gel, chemical vapor deposition (CVD), and pulsed laser deposition (PLD). Its compatibility with silicon technology also makes it appealing for integrated optics applications. However, like many bismuth compounds, it requires careful handling and processing due to the toxicity of bismuth. Overall, BTO's unique ferroelectric and electro-optic properties make it a material of keen interest for researchers exploring new avenues in photonic and optoelectronic devices.

Other names

  • Bismuth titanium oxide
  • Bismuth titanate oxide
  • Bismuth titanyl oxide

External links