Andrei Gorodetsky

Andrei Gorodetsky
University of Birmingham · School of Physics and Astronomy

PhD; Doctor of Science
Looking for a Lecturer / Assistant Professor / Senior Researcher Position

About

90
Publications
11,766
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,088
Citations
Introduction
THz and ultrafast laser experimental and simulations scientist with over 10 years of research experience.
Additional affiliations
August 2019 - present
University of Birmingham
Position
  • Research Associate
Description
  • THz imaging, metamaterials and more
December 2017 - August 2019
Imperial College London
Position
  • Research Associate
Description
  • THz pump-probe experiments
October 2016 - November 2017
Lancaster University
Position
  • Research Associate
Description
  • THz particle acceleration
Education
April 2017 - December 2019
ITMO University
Field of study
  • Optics
June 2006 - May 2010
ITMO University
Field of study
  • Optics
September 2003 - January 2006

Publications

Publications (90)
Article
Full-text available
Photoconductive antennas and photomixers are very promising sources of terahertz radiation that is widely used for spectroscopy, characterisation and imaging of biological objects, deep space studies, scanning of surfaces and detection of potentially hazardous substances. These antennas are compact and allow generation of both ultrabroadband pulse...
Article
Full-text available
Terahertz pulse time-domain holography (THz PTDH) is the powerful technique for high-resolution amplitude and phase THz imaging that allows mapping spectroscopic information across the imaged object. In this paper, we consider most sought after applications of phase imaging provided by this technique and experimentally demonstrate the ability of th...
Article
Full-text available
Advanced nanophotonics penetrates into other areas of science and technology, ranging from applied physics to biology and resulting in many fascinating cross-disciplinary applications. It has been recently demonstrated that suitably engineered light-matter interactions at the nanoscale can overcome the limitations of today's terahertz (THz) photoco...
Article
Full-text available
Compact and tunable semiconductor terahertz sources providing direct electrical control, efficient operation at room temperatures and device integration opportunities are of great interest at the present time. One of the most well-established techniques for terahertz generation utilises photoconductive antennas driven by ultrafast pulsed or dual-wa...
Article
We demonstrate an ultra-compact, room-temperature, tunable terahertz (THz) generating laser source based on difference-frequency-driven photomixing in a coplanar stripline InAs/GaAs quantum-dot (QD) antenna pumped by a broadly-tunable, high-power, continuous wave InAs/GaAs QD laser diode in the double-grating quasi-Littrow configuration. The dual-w...
Article
Full-text available
Fundamental mechanisms underlying exciton formation in organic semiconductors are complex and elusive as it occurs on ultrashort sub-100-fs timescales. Some fundamental aspects of this process, such as the evolution of exciton binding energy, have not been resolved in time experimentally. Here, we apply a combination of sub-10-fs Pump-Push-Photocur...
Article
In this paper, we review the existing approaches for vortex and vector beam shaping and generation in the terahertz frequency range. The particular focus of this review is on the possibility of homogeneous topological charge formation in the ultra-wide spectral interval inherent to ultrashort terahertz pulses. We review the available materials and...
Article
In this paper, we demonstrate the capabilities of the terahertz pulse time-domain holography in visualisation, simulation, and assessment of broadband THz vortex beam formation dynamics upon its shaping by elements of beam converter, and further propagation and manipulation. By adding Jones matrix formalism to describe broadband optical elements, w...
Conference Paper
We apply ultrafast pump-push-photocurrent and pump-push-photoluminescence spectroscopies to polyfluorene organic diode to track in time the bound exciton formation. ‘Cold’-excitons become bound within 10-fs while ‘hot’-excitons can dissociate spontaneously within 50-fs before acquiring bound character.
Conference Paper
In this contribution, we discuss the features of design and polarimetric inspection of terahertz achromatic waveplates. The design of the crystalline quartz half-wave plate was performed taking into account the ellipticity and the introduced phase difference between the orthogonal components of the output radiation polarization vector. The designed...
Article
Photoconductive antennas deposited onto GaAs substrates that incorporate InAs quantum dots have been recently shown to efficiently generate both pulsed and CW terahertz radiation. In this Letter, we determine the operational limits of these antennas and demonstrate their extreme thermal breakdown tolerance. Implanted quantum dots serve as free carr...
Article
Full-text available
We present the numerical, theoretical, and experimental study of a terahertz metasurface supporting a pseudo-anapole. Pseudo-anapole effect arises when electric and toroidal dipole moments both tend to a minimum, instead of destructive interference between electric and toroidal dipole moments in conventional anapole mode. Such overlap allows resona...
Conference Paper
The realisation of hyperspectral terahertz imaging is a signi�cant step towards understanding of the life sciences on all scales. A key to this understanding is the retrieval of dielectric properties from such images, a task which is plagued by experimental limitations, challenging the terahertz community for more than two decades. In this contribu...
Preprint
The behavior of hot carriers in metal-halide perovskites (MHPs) present a valuable foundation for understanding the details of carrier-phonon coupling in the materials as well as the prospective development of highly efficient hot carrier and carrier multiplication solar cells. Whilst the carrier population dynamics during cooling have been intense...
Article
In nature, sensory photoreceptors underlie diverse spatiotemporally precise and generally reversible biological responses to light. Photoreceptors also serve as genetically encoded agents in optogenetics to control by light organismal state and behavior. Phytochromes represent a superfamily of photoreceptors that transition between states absorbing...
Conference Paper
This work demonstrates the encoding principle for wave trains consisting of interfering uniformly charged Laguerre-Gaussian terahertz beams carrying unitary and zero topological charges. Optimization of the receiving aperture and threshold for a binary encoding outcome is presented.
Article
Full-text available
To undertake THz spectroscopy and imaging, and accurately design and predict the performance of quasi-optical components, knowledge of the parameters of the beam (ideally Gaussian) emitted from a THz source is paramount. Despite its proliferation, relatively little work has been done on this in the frame of broadband THz photoconductive antennas. U...
Conference Paper
Full-text available
In this contribution, we investigate the features of the two-beam interference of a set of wave trains, in which one of the beams contains an orbital angular momentum caused by the presence of inline topologically charged vortices in each spectral component. The infrared pump beam that generates terahertz radiation is first doubled in Mach-Zehnder...
Article
The relaxation of high-energy “hot” carriers in semiconductors is known to involve the redistribution of energy between hot and cold carriers, as well as the transfer of energy from hot carriers to phonons. Over the past few years, these two processes have been identified in lead-halide perovskites (LHPs) using ultrafast pump-probe experiments, but...
Article
Carrier cooling is of widespread interest in the field of semiconductor science. It is linked to carrier-carrier and carrier-phonon coupling, and has profound implications for the photovoltaic performance of materials. Recent transient optical studies have shown that a high carrier density in lead-halide perovskites (LHPs) can reduce the cooling ra...
Article
Full-text available
The novel concept of an all-dielectric terahertz metasurface for amplitude and phase modulation is proposed. The results of numerical simulation of transmittance and phase shift of a broadband input THz signal are presented. The change of the amplitude and phase characteristics of the metasurface under the laser irradiation of the metasurface is sh...
Article
The hydrothermal method is the most effective approach for the synthesis of VO2 metastable polymorphes with unique powder crystallites morphology. In this work, we expanded the capabilities of this method, directing it to the growth of oriented crystallites in self-organized systems on the single crystal substrates. According to our investigations,...
Preprint
Full-text available
The relaxation of high-energy "hot" carriers in semiconductors is known to involve the redistribution of energy between (i) hot and cold carriers and (ii) hot carriers and phonons. Over the past few years, these two processes have been identified in lead-halide perovskites (LHPs) using ultrafast pump-probe experiments, but the interplay between the...
Article
Here, we present a comprehensive study of the reconstruction quality in terahertz (THz) pulse time-domain holography. We look into single wavelength reconstructions, as well as broadband recovery enabled by the ultrabroadband nature of radiation and coherent detection enabled by electro-optic or photoconductive sensing. We demonstrate the transvers...
Article
When calculated in the spectral domain, the propagation of an ultrashort optical pulse may suffer from inaccuracy due to the finite thickness of the object it diffracts on. Unlike monochromatic radiation, ultrashort pulse interaction with an object in the time domain depends on the pulse longitudinal coordinate. Here, we propose an algorithm to stu...
Article
In this paper, we study the behavior of photoexcited carriers in GaAs wafers containing self-assembled InAs quantum dots (QDs). These samples were designed and grown to be employed as photoconductive antennae for terahertz (THz) generation. The implanted QDs serve to shorten the overall carrier lifetime and enable pumping with lasers operating at w...
Article
Full-text available
We propose, fabricate, and evaluate strain-induced InGaAs/InAlAs superlattice (SL), which can efficiently radiate broadband terahertz (THz) waves. By means of optical pump-probe measurements, we demonstrate ultrashort photocarriers relaxation times of τ=1.7 ps without Be-doping of InGaAs photoconductive layers. We assume two dominant mechanisms to...
Article
In this paper, we show the approach to enhance the optical properties of the plasmonic nanowires from the perspectives of both field enhancement and tunability. Two different cases have been suggested for the consideration: the first one uses hollow-core metamaterial interface, while the other involves metallic nanowire metamaterial interface. It h...
Article
Full-text available
A comprehensive characterization of the diffraction properties of terahertz (THz) pulsed broadband vortex beams consisting of several electromagnetic field oscillations requires state-of-the-art techniques for studying the evolution of a wavefront as it propagates. For this purpose, we have applied the capabilities offered by THz pulse time domain...
Article
Full-text available
Abstract In this paper, we present a novel numerical approach for increasing the resolution of retrieved images of objects after their diffraction patterns are recorded via terahertz pulse time-domain holography (THz PTDH). THz PTDH allows for spectrally resolved imaging with high spatial resolution and does not require the fine alignment of comple...
Conference Paper
In this paper, basic principles of broadband femtosecond pulse propagation through an amplitude and phase object are presented. A novel approach of stepwise progressive propagation through the object is introduced and discussed. A comparative analysis of “progressively” and “simultaneously” propagated femtosecond pulses is presented. The algorithm...
Article
Full-text available
Herein, we numerically investigate terahertz photoconductive antennas (PCAs) based on optimized plasmonic nanostructures and absorption enhancement in nanocylinders. Plasmonic behavior in the visible to near-infrared light spectrum is achievable due to the metallic nanostructure employment. Herein, we study the absorption enhancement of silver and...
Article
Full-text available
We demonstrate the results of on THz emission from hybrid THz photoconductive antenna loaded with silver nanoantenna. The results of experimental investigations are in a good agreement with numerical simulations presented in our recent work. The conversion efficiency reveals over 5-fold improvement at certain frequencies, if compared with similar p...
Article
The rapid relaxation of above-bandgap “hot” carriers (HCs) imposes the key efficiency limit in lead-halide perovskite (LHP) solar cells. Recent studies have indicated that HC cooling in these systems may be sensitive to materials composition, as well as the energy and density of excited states. However, the key parameters underpinning the cooling m...
Preprint
We study the influence of residual strain in InGaAs/InAlAs superlattice (SL) on the ultrafast photocarrier dynamics under femtosecond laser excitation. We propose and fabricate a novel-designed strained InGaAs/InAlAs SL which allows us to obtain an ultrashort photocarrier relaxation time of $\tau\sim$ 1.5 ps without Be-doping of the InGaAs photocon...
Article
Electronic degrees of freedom are predicted to play a significant role in mechanics of two-dimensional crystalline membranes. Here we show that appearance of charge carriers may cause a considerable impact on suspended graphene corrugation, thus leading to additional mechanism resulting in charge carriers mobility variation with their density. This...
Article
Full-text available
We present the results of hybrid photoconductive antenna THz emission enhanced by silver nanoantenna arrays. By varying the size of nanoantennas and the distance between them, we obtain the greatest value of optical-to-THz conversion efficiency reached so far. The results of experimental investigations are in a good agreement with numerical simulat...
Conference Paper
Photoelectric properties of an InAs/GaAs QD-based photoconductive THz antenna are extensively studied. The temperature dependence of conductivity spectra reveals different roles of thermal and tunneling carrier escape mechanisms for the ground and excited state pumping.
Conference Paper
Tunable terahertz generation with a maximum output power of 0.6 nW at 0.83 THz was demonstrated from a coplanar stripline InAs/GaAs quantum dot antenna pumped by a compact broadly-tunable dual-wavelength InAs/GaAs quantum dot external-cavity laser.
Article
In this paper, the study of the photoconductivity in self-assembled InAs/GaAs quantum dot photoconductive antenna in the wavelength region between 1140 nm and 1250 nm at temperatures ranging from 13 K to 400 K is reported. These antennas are aimed to work in conjunction with quantum dot semiconductor lasers to effectively generate pulsed and CW ter...
Conference Paper
Novel materials, notably quantum-dot (QD) semiconductor structures offer the unique possibility of combining exploitable spectral broadening of both gain and absorption with ultrafast carrier dynamic properties. Thanks to these characteristics QD-based devices have enhanced the properties of CW devices as well as development of compact ultrashort p...
Cover Page
Development of compact and efficient room temperature CW and pulsed THz sources is a vital and open question. The use of photoconductive antennas is effective way to generate THz radiation, but they suffer from relatively low conversion efficiency. Recently, an approach to solving this problem based on placing of optical nanoantennas inside the ant...
Conference Paper
We present our recent results on CW and pulsed THz generation in quantum dot (QD) based photoconductive antennae (PCA) pumped by ultrafast and dual wavelength semiconductor lasers. QDPCA substrate incorporates InAs QDs in GaAs matrix, thus keeping semiconductor carrier mobility at higher levels that is typical for SI GaAs, while QDs themselves serv...
Article
Full-text available
The future generation of modern illumination should not only be cheap and highly efficient, but also demonstrate high quality of light, light which allows better color differentiation and fidelity. Here we are presenting a novel approach to create a white solid-state light source providing ultimate color rendition necessary for a number of applicat...
Conference Paper
Full-text available
We have investigated the mode-lock operation from a semiconductor optical amplifier (SOA) gain chip in the ring fibre configuration. At lower pump currents, the laser generates dark soliton pulses both at the fundamental repetition rate of 39 MHz and supports up to the 6th harmonic order corresponding to 234-MHz repetition rate with an output powe...