A misprint in our manuscript published in Opt. Express32(5), 7030 (2024) 10.1364/OE.
View Article and Find Full Text PDFA new type of terahertz source containing only two optical elements - a volume phase holographic grating, and a semiconductor nonlinear slab - is proposed. The setup does not require any microstructuring, has only one diffraction order, and can be scaled to large pump sizes without any principal limitations. Furthermore, it can be easily adapted to different pump wavelengths and THz phase-matching frequencies.
View Article and Find Full Text PDFOpen-aperture Z-scan measurements have been carried out to investigate the three-photon (3 PA) and four-photon absorption (4 PA) coefficients at 800 nm and 1030 nm wavelengths, respectively in congruent and stoichiometric lithium niobate (cLN, sLN) with different concentrations of Mg doping. The laser pulse duration at the two wavelengths were 40 and 190 fs. The peak intensity inside the crystals varied between approximately 110 and 550 GW/cm.
View Article and Find Full Text PDFIn the last decade, intense research has been witnessed on developing compact, terahertz (THz) driven electron accelerators, producing electrons with a sub-MeV-few tens of MeV energy. Such economical devices could be used in scientific and material research and medical treatments. However, until now, the extremely high-energy THz pulses needed by the THz counterparts of the microwave accelerators were generated by optical rectification (OR) of ultrafast Ti:sapphire or Yb laser pulses.
View Article and Find Full Text PDFLight Sci Appl
October 2023
Optical rectification of femtosecond laser pulses has emerged as the dominant technique for generating single- and few-cycle terahertz (THz) pulses. The advent of the tilted pulse front pumping (TPFP) velocity matching technique, proposed and implemented two decades ago, has ushered in significant advancements of these THz sources, which are pivotal in the realm of THz pump-probe and material control experiments, which need THz pulses with microjoule energies and several hundred kV/cm electric field strengths. Furthermore, these THz sources are poised to play a crucial role in the realization of THz-driven particle accelerators, necessitating millijoule-level pulses with tens of MV/cm electric field strengths.
View Article and Find Full Text PDFA novel, to the best of our knowledge, compact, imaging-free, tilted-pulse-front (TPF) pumped terahertz (THz) source based on a LiNbO slab with a small wedge angle (< 8°) and with an echelon microstructure on its input surface has been demonstrated. Single-cycle pulses of more than 40-µJ energy and 0.28-THz central frequency have been generated by 100-mJ, 400-fs pump pulses with 4.
View Article and Find Full Text PDFIn recent years several microstructured lithium niobate THz pulse source were suggested for high-energy applications. Two types of those, the reflective and the transmissive nonlinear slab are adopted here for semiconductors. These new sources are scalable both in THz energy and size.
View Article and Find Full Text PDFWe present an improved model for electron acceleration in vacuum with high-energy THz pulses that includes spatiotemporal effects. In our calculations, we examined the acceleration with 300 GHz and 3.0 THz central frequency THz pulses with properties corresponding to common sources, and compared the Gaussian and Poisson spectral amplitudes and the associated time profiles of the electric fields.
View Article and Find Full Text PDFObjective: One-third of the Hungarian population suffers from xerostomia. Since there is no evidence of the actual prevalence of Sjögren's syndrome (SS) in Hungary, this study aimed to evaluate the same.
Materials And Methods: Data were collected from the Faculty of Dentistry, Semmelweis University from 2008 to 2015.
A novel THz source, based on optical rectification in LiNbO using the tilted-pulse-front technique, is proposed and experimentally demonstrated. The pulse-front tilt is introduced by a volume phase holographic grating, efficiently used at perpendicular incidence in transmission, and the THz pulses are produced in a LiNbO plane-parallel nonlinear echelon slab, arranged parallel to the grating. As a unique feature, the entire setup has a plane-parallel, transmission-type configuration, which straightforwardly enables distortion-free scaling to large sizes, high pulse energies and high THz field strengths.
View Article and Find Full Text PDFA new type of THz source, working in reflection geometry, is proposed, where the pulse-front-tilt is introduced by a periodically micro-structured metal profile. For optical coupling, high refractive index nanocomposite fluid is used between the nonlinear optical material and the structured metal surface. Numerical simulations predict ∼87 and ∼85% optimized diffraction efficiencies for lithium niobate and lithium tantalate at 1030 and 800 nm pump wavelengths.
View Article and Find Full Text PDFA tilted-pulse-front pumped terahertz pulse source is proposed for the generation of extremely high field single-cycle terahertz pulses. The very simple and compact source consists of a single crystal slab having a blazed reflection grating grooved in its back surface. Its further important advantages are the energy scalability and the symmetric THz beam profile.
View Article and Find Full Text PDFRecently a hybrid-type terahertz (THz) pulse source was proposed for high energy terahertz pulse generation. It is the combination of the conventional tilted-pulse-front setup and a nonlinear crystal with a transmission stair-step echelon of period in the hundred-micrometer range etched into the front face. The tilt angle introduced by the conventional tilted-pulse-front setup (pre-tilt) was chosen to be equal to the tilt-angle needed inside the nonlinear crystal (62° for lithium niobate (LN)) in order to fulfill velocity-matching.
View Article and Find Full Text PDFA new type of tilted-pulse-front pumped terahertz (THz) source has been demonstrated, which is based on a LiNbOplane-parallel slab with an echelon structure on its input surface. Single-cycle pulses of 1 μJ energy and 0.30 THz central frequency have been generated with 5×10 efficiency from such a source.
View Article and Find Full Text PDFResearch at modern light sources continues to improve our knowledge of the natural world, from the subtle workings of life to matter under extreme conditions. Free-electron lasers, for instance, have enabled the characterization of biomolecular structures with sub-ångström spatial resolution, and paved the way to controlling the molecular functions. On the other hand, attosecond temporal resolution is necessary to broaden our scope of the ultrafast world.
View Article and Find Full Text PDFA hybrid-type terahertz pulse source is proposed for high energy terahertz pulse generation. It is the combination of the conventional tilted-pulse-front setup and a transmission stair-step echelon-faced nonlinear crystal with a period falling in the hundred-micrometer range. The most important advantage of the setup is the possibility of using plane parallel nonlinear optical crystal for producing good-quality, symmetric terahertz beam.
View Article and Find Full Text PDFHealth-related quality of life (HRQoL) is an important outcome in oncology care although an underexplored area in bladder cancer (BC). Our aims were to assess HRQoL of patients with BC, analyse relationships between diverse HRQoL measures and validate the Hungarian version of the Bladder Cancer Index (BCI) questionnaire. A cross-sectional survey was performed among patients with BC (N = 151).
View Article and Find Full Text PDFBackground: The majority of men will develop symptoms of benign prostatic hyperplasia (BPH) after 70 years of age. Various studies indicate that antagonists of LHRH, such as cetrorelix, exert direct inhibitory effects on BPH mediated by specific LHRH receptors. Our aim was to investigate the mRNA for LHRH and LHRH receptors and the expression of LHRH receptors in specimens of human BPH.
View Article and Find Full Text PDFThe presence of four different isoforms of luteinizing hormone-releasing hormones (LHRH) and one LHRH receptor (LHRH-R) has been reported in vertebrates. In the human genome only LHRH-I and LHRH-II genes have been identified. The human LHRH-I gene is composed of four exons separated by three introns.
View Article and Find Full Text PDFJ Laparoendosc Adv Surg Tech A
October 2007
In this paper, the authors report on a new, modified laparoscopic technique to remove a large bladder diverticulum. A 26-year-old male with a urinary problem underwent an ultrasound, as well as intravenous urography and cystoscopy examinations, which showed a large bladder diverticulum. The diverticulum was operated upon laparoscopically.
View Article and Find Full Text PDFWe report on an 11-weeks pregnant woman, who under went a percutaneous nephrolithotomy without the use of X-rays during the procedure due to 8-mm left upper ureteric stone. In the available literature, we didn't find any reported case about percutaneous stone removal without the use of X-rays.
View Article and Find Full Text PDFThe idiopathic inflammatory myopathies are systemic autoimmune diseases characterized by chronic inflammation leading to progressive weakness of the proximal muscles. In 7-66% of cases of adult dermatomyositis different malignant tumours can promote the difficult cascade mechanisms at the cell level, leading to rapid weakness of skeletal muscles [1]. We report on a patient with all characteristic signs of acute, severe dermatomyositis associated with a low-grade, low-stage prostate cancer cured by radical perineal prostatectomy.
View Article and Find Full Text PDFUnlabelled: In the paediatric section, two papers relating to the upper urinary tract are presented. The first, from Hungary, describes simultaneous bilateral percutaneous nephrolithotomy in 13 patients, where it was deemed feasible; this is the first such report. Authors from London report on unilateral nephrectomy in patients with nephrogenic hypertension, and found that it was successful in normalising blood pressure in patients with renal hypertension with a normal contralateral kidney.
View Article and Find Full Text PDFPurpose: We studied the detection of primary prostate cancer with positron emission tomography (PET) using C-labeled methionine (MET) in patients with increased prostate specific antigen (PSA) levels and repeatedly negative biopsies.
Materials And Methods: A total of 20 consecutive patients with increased serum PSA and negative repeat biopsies were included in the study. Patient age ranged from 52 to 75 years (average 65).