New application of terahertz time-domain spectrometry (THz-TDS) to the phonon-polariton observation on ferroelectric crystals.
A new instrument for terahertz time-domain spectroscopy (THz-TDS) has been developed. It consists of a composite THz-TDS system and a high throughput (Martin-Puplett) interferometer. The instrument is for use in the qualitative study of optoelectronic constants of materials. The spectral transmission intensity and phase shift related to phonon-polariton dispersion have been measured between 100 cm(-1) and 3 cm(-1) on ferroelectric crystals of industrial interest. These include bismuth titanate Bi4Ti3O12 (a key material for FeRAM), lithium niobate LiNbO3 (a typical nonlinear crystal for parametric oscillator applications) and lithium heptagermanate Li2Ge7O15 for surface elastic wave filter applications. The complex dielectric constants are well reproduced by the phonon-polariton dispersion relation based on the Kurosawa formula. The instrument details and phonon-polariton dispersion results are described.
Nishizawa
Seizi
S
Cooperative Research Center, Shinshu University, Nagano 380-8553, Japan.
Tsumura
Naoki
N
Kitahara
Hideaki
H
Wada Takeda
Mitsuo
M
Kojima
Seiji
S
D016880:Anisotropy; D001729:Bismuth / Q000737:chemistry; D003460:Crystallization / Q000379:methods; D003461:Crystallography / Q000295:instrumentation* / Q000379:methods; D055590:Electromagnetic Phenomena / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005290:Ferric Compounds / Q000737:chemistry*; D007368:Interferometry / Q000295:instrumentation* / Q000379:methods; D007834:Lasers; D018020:Lithium Compounds / Q000737:chemistry; D008422:Materials Testing / Q000295:instrumentation*; D008962:Models, Theoretical; D009556:Niobium / Q000737:chemistry; D055095:Optics and Photonics / Q000295:instrumentation; D010087:Oxides / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D012542:Scattering, Radiation; D013057:Spectrum Analysis / Q000295:instrumentation* / Q000379:methods; D014025:Titanium / Q000737:chemistry
D005290:Ferric Compounds; D018020:Lithium Compounds; D010087:Oxides; D009556:Niobium; C091692:lithium niobate; C001215:ferrite; D014025:Titanium; D010100:Oxygen; D001729:Bismuth