High-power terahertz-wave generation using DAST crystal and detection using mid-infrared powermeter.
The exact power output of a table-top-sized terahertz (THz)-wave source using a nonlinear optical process has not been clarified because detectors for these experiments [Si bolometer, deuterated triglycine sulfate (DTGS), etc.] are not calibrated well. On the other hand, powermeters for the mid-infrared (mid-IR) region are well established and calibrated. We constructed a high-power dual-wavelength optical parametric oscillator with two KTP crystals as a light source for difference frequency generation. The obtained powers of dual waves were 21 mJ at ~1300 nm, ten times higher than that of the previous measurement. The device provides high-power THz-wave generation with ~100 times greater output power than that reported in previous works. A well-calibrated mid-IR powermeter at ~27 THz detected the generated THz wave; its measured energy was 2.4 microJ. Although the powermeter had no sensitivity in the lower-frequency range (below 20 THz), the pulse energy at such a low-frequency region was estimated in reference to the output spectrum obtained using a DTGS detector: the energy would be from about the submicrojoule level to a few microjoules in the THz-wave region.
Suizu
Koji
K
Research Institute of Electrical Communication, Tohoku University, Japan. suizu@nuee.nagoya-u.ac.jp
Miyamoto
Katsuhiko
K
Yamashita
Tomoyu
T
Ito
Hiromasa
H
D004867:Equipment Design; D019544:Equipment Failure Analysis; D007259:Infrared Rays; D008872:Microwaves; D055095:Optics and Photonics / Q000295:instrumentation*; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D012680:Sensitivity and Specificity; D014159:Transducers