研究目的
Investigating the measurement of the time-resolved electric field and its conjugate variable in ultrabroadband electro-optic sampling.
研究成果
The study demonstrates the measurement of the time-resolved electric field and its conjugate variable in both critically phase-matched and isotropic nonlinear crystals. The balance of sum and difference frequency generation between multi-THz and probe pulses is identified as a crucial parameter. The findings are essential for the implementation of a full quantum tomography in the time domain.
研究不足
The imperfect retardation of the achromatic waveplate limits the suppression of the spectrally integrated HWP signal, leading to a finite admixture of the ellipticity signal. Additionally, the balance of sum and difference frequency generation processes is crucial for the measurement of the conjugate variable, requiring careful selection of detection crystals and spectral filtering.
1：Experimental Design and Method Selection:
The experiment is based on an Er:fiber front-end providing two outputs at 20 (pump branch) and 40 MHz (probe branch). Highly nonlinear fiber assemblies enable generation of few-fs pulses in the near-infrared spectral region. Using the pump branch, phase-stable multi-THz transients are generated by intra-pulse difference frequency generation (DFG) in a GaSe crystal. Probe pulses are superimposed with the multi-THz field in an electro-optic detection crystal followed by a typical ellipsometry setup. A quarter-wave plate (QWP) or a half-wave plate (HWP) is used in combination with a Wollaston prism to separate the two orthogonal polarization components. A balanced detector measures the ellipticity induced in the probe beam by nonlinear mixing with an infrared waveform in a suitable crystal. The balanced photocurrent is then detected using lock-in amplification at 20 MHz.
2：Sample Selection and Data Sources:
Samples include uniaxial AgGaS2 and zincblende-type ZnTe crystals.
3：List of Experimental Equipment and Materials:
Er:fiber front-end, GaSe crystal, AgGaS2 crystal, ZnTe crystal, quarter-wave plate (QWP), half-wave plate (HWP), Wollaston prism, balanced detector, lock-in amplifier.
4：Experimental Procedures and Operational Workflow:
The delay between multi-THz and probe pulses is varied to sample the electric field in the time domain. Spectrally resolved measurements are performed by applying bandpass filters after the nonlinear interaction.
5：Data Analysis Methods:
The electro-optic signals are analyzed concerning changes in ellipticity and tilting of the polarization ellipsoid. Spectrally resolved measurements provide insights into the contributions of sum and difference frequency generation processes.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容-
Er:fiber front-end
Provides two outputs at 20 (pump branch) and 40 MHz (probe branch) for generating few-fs pulses in the near-infrared spectral region.
-
GaSe crystal
Used for intra-pulse difference frequency generation (DFG) to generate phase-stable multi-THz transients.
-
AgGaS2 crystal
Used as an electro-optic detector for measuring minute changes in the ellipticity corresponding to tiny field amplitudes.
-
ZnTe crystal
Used as an electro-optic detector with cubic symmetry for analyzing polarization tilt and ellipticity changes.
-
quarter-wave plate (QWP)
Used in combination with a Wollaston prism to separate the two orthogonal polarization components for measuring ellipticity changes.
-
half-wave plate (HWP)
Used to measure polarization tilt by replacing the QWP in the ellipsometer setup.
-
Wollaston prism
Used to separate the two orthogonal polarization components after the nonlinear interaction in the detection crystal.
-
balanced detector
Measures the ellipticity induced in the probe beam by nonlinear mixing with an infrared waveform.
-
lock-in amplifier
Detects the balanced photocurrent at 20 MHz for precise measurement of the electro-optic signals.
-
登录查看剩余7件设备及参数对照表
查看全部
