Terahertz-wave absorption in GaP crystals with different carrier densities

K. Saito, T. Tanabe, Y. Oyama, K. Suto, T. Kimura, J. Nishizawa

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)


Using a GaP Raman-based THz-wave (GRT) generator spectrometer in the frequency range 0.8-5 THz, we measured the terahertz (THz) wave absorption spectra of GaP crystals with carrier densities of 1010 and 1016 cm-3. We also investigated the temperature dependence from 20 to 300 K. In the lower-carrier-density GaP, the THz-wave absorption by phonons increased from 1.5 to 7 cm-1 as the THz frequency increased. In the higher-carrier-density GaP, absorption due to free carriers appeared below 2.5 THz. The THz-wave absorption decreased as a function of crystal temperature in each sample (α<2 cm-1 at 20 K). We also measured the temperature dependence of the THz-wave output from the GaP crystals. In each crystal, the THz-wave output was enhanced at 90 K, compared with room temperature, due to the decrease in the THz-wave absorption.

Original languageEnglish
Pages (from-to)597-600
Number of pages4
JournalJournal of Physics and Chemistry of Solids
Issue number2-3
Publication statusPublished - 2008 Feb
Externally publishedYes


  • A. Optical materials
  • A. Semiconductors
  • C. Infrared spectroscopy
  • D. Optical properties

ASJC Scopus subject areas

  • General Chemistry
  • General Materials Science
  • Condensed Matter Physics


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