We present a comparative study of nonlinear optical materials for terahertz pulse generation by optical rectification and detection by electro-optic sampling, with the aim to find a material the is best suited for the use together with femtosecond lasers operating at a wavelength of 1.5 μm. Three crystals are identified that fulfill
the condition that the optical group velocity matches the terahertz phase velocity: the organic salt DAST and
the inorganic semiconductors GaAs and ZnTe, the latter showing velocity-matching with the second harmonic
of 1.5 μm. A combined figure of merit for optical rectification and electro-optic sampling is derived. For the
three materials under consideration, we find numerical values of 4300 (DAST):110 (GaAs):370 (ZnTe), in units
of (pm/V)2. We also present experimental evidence that the performance of DAST is an order of magnitude
better than those of the inorganic semiconductors, and we present spectroscopic data in the terahertz range of
DSMOS, a chemical derivative of DAST that may in the future also be used for terahertz applications.
Short THz pulses are commonly generated through the optical rectification of ultrashort laser pulses in nonlinear optical crystals. Our purpose is to discuss the controllability of the THz spectrum emitted from the polar organic salt DAST (4-N,N-dimethylamino-4-N-methyl stilbazolium tosylate) and also the efficiency of the THz generation. It does not only depend on different experimental parameters such as duration of the laser pulse and crystal thickness, but is also affected by absorption and dispersion caused by several resonances of the crystal in the THz range.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.