TY - JOUR

T1 - Specific features of studying anisotropic media by methods of time-domain terahertz spectroscopy

AU - Antsygin, V. D.

AU - Losev, V. F.

AU - Mamrashev, A. A.

AU - Nikolaev, N. A.

AU - Potaturkin, O. I.

PY - 2016/7/1

Y1 - 2016/7/1

N2 - Wide-band time-domain terahertz (THz) spectroscopy is a popular method of studying optical properties of various materials. This method is considered as applied to polarization-sensitive measurements of properties of anisotropic materials and media possessing significant dichroism and birefringence. It is important to understand that the development of the elemental base for the terahertz range, in particular, for THz polarizers, falls behind the achievements of polarization optics for the visible range. In studying anisotropic materials, this may lead to simultaneous detection of orthogonal components of the THz field and to formation of artifacts in the spectral range in calculations of properties of examined samples. A unique specific feature of time-domain terahertz spectroscopy, namely, a possibility of capturing the time-dependent shape of the THz pulse, allows separation of the orthogonal components of the field in the time domain. Thus, it is possible to detect the signal from radiation with the orthogonal polarization and eliminate it by means of appropriate adjustment of polarization elements of the spectroscopy system. This method is demonstrated by an example of studying the terahertz properties along the optical axis z of an anisotropic ferroelectric crystal of lead germanate in which significant birefringence and dichroism arise as the crystal is heated to the phase transition temperature.

AB - Wide-band time-domain terahertz (THz) spectroscopy is a popular method of studying optical properties of various materials. This method is considered as applied to polarization-sensitive measurements of properties of anisotropic materials and media possessing significant dichroism and birefringence. It is important to understand that the development of the elemental base for the terahertz range, in particular, for THz polarizers, falls behind the achievements of polarization optics for the visible range. In studying anisotropic materials, this may lead to simultaneous detection of orthogonal components of the THz field and to formation of artifacts in the spectral range in calculations of properties of examined samples. A unique specific feature of time-domain terahertz spectroscopy, namely, a possibility of capturing the time-dependent shape of the THz pulse, allows separation of the orthogonal components of the field in the time domain. Thus, it is possible to detect the signal from radiation with the orthogonal polarization and eliminate it by means of appropriate adjustment of polarization elements of the spectroscopy system. This method is demonstrated by an example of studying the terahertz properties along the optical axis z of an anisotropic ferroelectric crystal of lead germanate in which significant birefringence and dichroism arise as the crystal is heated to the phase transition temperature.

KW - birefringence

KW - dichroism

KW - ferroelectric

KW - lead germanate

KW - polarization-optical detection

KW - terahertz radiation

KW - terahertz spectroscopy

UR - http://www.scopus.com/inward/record.url?scp=84991678381&partnerID=8YFLogxK

U2 - 10.3103/S8756699016040099

DO - 10.3103/S8756699016040099

M3 - Article

AN - SCOPUS:84991678381

VL - 52

SP - 374

EP - 380

JO - Optoelectronics, Instrumentation and Data Processing

JF - Optoelectronics, Instrumentation and Data Processing

SN - 8756-6990

IS - 4

ER -