0000000000027530
AUTHOR
Matteo Clerici
Solid-state-biased coherent detection of ultra-broadband terahertz pulses
Significant progress in nonlinear and ultrafast optics has recently opened new and exciting opportunities for terahertz (THz) science and technology, which require the development of reliable THz sources, detectors, and supporting devices. In this work, we demonstrate the first solid-state technique for the coherent detection of ultra-broadband THz pulses (0.1-10 THz), relying on the electric-field-induced second-harmonic generation in a thin layer of ultraviolet fused silica. The proposed CMOS-compatible devices, which can be realized with standard microfabrication techniques, allow us to perform ultra-broadband detection with a high dynamic range by employing probe laser powers and bias v…
Invited Article: Ultra-broadband terahertz coherent detection via a silicon nitride-based deep sub-wavelength metallic slit
We present a novel class of CMOS-compatible devices aimed to perform the solid-state-biased coherent detection of ultrashort terahertz pulses, i.e., featuring a gap-free bandwidth at least two decades-wide. Such a structure relies on a 1-µm-wide slit aperture located between two parallel aluminum pads, embedded in a 1-µm-thick layer of silicon nitride, and deposited on a quartz substrate. We show that this device can detect ultra-broadband terahertz pulses by employing unprecedented low optical probe energies of only a few tens of nanojoules. This is due to the more than one order of magnitude higher nonlinear coefficient of silicon nitride with respect to silica, the nonlinear material emp…
Counter-propagating difference frequency mixing in diamond with terahertz waves
We investigate four-wave mixing between terahertz and optical pulses in diamond. We observe the occurrence of sum and difference frequency generation, with the latter being phase-matched for terahertz pulses counter-propagating to the optical field.
3084329.pdf
Supplementary Materials
Exact reconstruction of thz sub-λ source features in knife-edge measurements
The spatial features of a sub-wavelength terahertz source are not accessible using time-integrated knife-edge techniques due to the non-separable space-time nature of the radiated field and to systematic modifications induced by the blade itself. We show that combining knife-edge with a time resolved electro-optical sampling, the space-time coupling can be addressed and the source field profile can be exactly reconstructed.
Affordable, ultra-broadband coherent detection of terahertz pulses via CMOS-compatible solid-state devices
We demonstrate the first fully solid-state technique for the coherent detection of ultra-broadband THz pulses (0.1-10 THz), relying on the electric-field-induced second-harmonic generation attained in integrated CMOS-compatible devices.
Observation of collapse arrest in pure kerr media sustained by a parametric interaction
We demonstrate a parametric interaction based on four wave mixing that can arrest the collapse and stabilize solitary propagation in a pure Kerr material by controlling the wavelength of the interacting beams.
Space-time features of THz emission from optical rectification in sub-wavelength areas
We present our investigation on the THz space-time emission characteristic induced by the non-paraxial generation regime in highly localized THz generation via optical rectification on sub-wavelength areas.
Asymmetric Dual-Grating Micro-Slit Configuration for Broadband Solid State Coherent Detection of THz Pulses
We demonstrated solid-state broadband coherent Terahertz characterization based on the Terahertz Field Induced Second Harmonic effect in Silica. The THz detector consists of an asymmetric micro-slit array which can be operated at 200V applied bias.
Silicon nitride-based deep sub-λ slit for ultra-broadband THz coherent detection
We report on the characterization of a new type of CMOS-compatible device for terahertz solid-state biased coherent detection, which relies on a 1-µm-wide metallic slit embedded in a thin film of PECVD-grown silicon nitride.
Counter-propagating frequency mixing with Terahertz waves in diamond
Frequency conversion by means of Kerr nonlinearity is one of the most common and exploited nonlinear optical processes in the UV, visible, IR, and mid-IR spectral regions. Here we show that wave mixing of an optical field and a terahertz wave can be achieved in diamond, resulting in the frequency conversion of the terahertz radiation either by sum- or difference-frequency generation. In the latter case, we show that this process is phase matched and most efficient in a counterpropagating geometry.
X-shaped space-time coherence in optical parametric generation
We study the spatiotemporal coherence properties of superfluorescence radiation generated in optical parametric amplification of quantum noise. We show that the angular dispersion properties of the spatiotemporal spectra, measured in different phase-matching conditions, lead to a clear X-shaped structure of the mutual correlation function of the radiation. Within a statistical picture, we interpret the generated superfluorescence as a stochastic “gas” of quasistationary modes characterized by a skewed correlation in the spatiotemporal domain, with characteristics similar to linear and nonlinear X waves not describable within a separable approach in space and time.
Emergence of X-Shaped Spatiotemporal Coherence in Optical Waves
Considering the problem of parametric nonlinear interaction, we report the experimental observation of electromagnetic waves characterized by an X-shaped spatiotemporal coherence; i.e., coherence is neither spatial nor temporal, but skewed along specific spatiotemporal trajectories. The application of the usual, purely spatial or temporal, measures of coherence would erroneously lead to the conclusion that the field is fully incoherent. Such hidden coherence has been identified owing to an innovative diagnostic technique based on simultaneous analysis of both the spatial and temporal spectra.
Spatio-temporal Characteristics of THz Emission at the Subwavelength Scale via Optical Rectification
Highly localized THz emission via optical rectification in thin nonlinear crystals is a promising method for subwavelength microscopy. We present here the peculiar THz spatio-temporal characteristics induced by the non-paraxial generation regime.
Counter-propagating difference-frequency generation in diamond with terahertz fields
The nonlinear interaction of terahertz (THz) pulses with optical fields in Kerr, gaseous media is a key ingredient for broadband THz detection schemes [1]. Terahertz field-induced second harmonic generation in solid-state media has also been considered for THz detection and as a tool e.g. for liquid dynamics investigations [2,3], while four-wave mixing has been addressed as a possible mechanism for THz generation [4,5]. © 2013 IEEE.
Experimental evidence of X-shaped spatiotemporal coherence of superfluorescence radiation
Considering the parametric generation process in a quadratic nonlinear crystal, we report the experimental observation of optical waves characterized by a X-shaped spatiotemporal coherence, i.e. a coherence skewed along spatiotemporal trajectories.