Full electro-optic terahertz time-domain spectrometer for polarimetric studies

Area of Science:

• Physics
• Spectroscopy
• Optics

Background:

• Terahertz (THz) time-domain spectroscopy is a powerful technique for material characterization.
• Polarimetric studies in the THz range require precise control over the THz beam's polarization state.
• Conventional methods often necessitate bulky and complex polarization control components at THz frequencies.

Purpose of the Study:

• To present a novel terahertz time-domain spectrometer optimized for polarimetric measurements.
• To demonstrate a method for controlling THz polarization directly via the excitation laser polarization.
• To eliminate the need for dedicated polarization controllers in THz spectroscopy setups.

Main Methods:

• Generation of THz pulses via optical rectification in a ⟨111⟩-cut cubic crystal.
• Detection of THz pulses using electro-optic sampling in a similar crystal.
• Implementation of a dual detection scheme to simultaneously measure two orthogonal THz polarization components.

Main Results:

• The spectrometer successfully generates THz pulses with polarization mirroring the excitation laser.
• Experimental results confirm that adjusting laser polarization directly controls THz beam polarization.
• Simultaneous measurement of dual polarization components was achieved.

Conclusions:

• The developed spectrometer offers an efficient and integrated approach to THz polarimetry.
• Controlling THz polarization through laser polarization simplifies experimental setups.
• This technique advances the capabilities for studying anisotropic materials and phenomena in the THz regime.