We study the second-harmonic generation in quadratic nonlinear media with localized spatial modulation of χ((2)) response. We demonstrate that the emission of Čerenkov second-harmonic takes place only when the fundamental beam illuminates the region of χ((2)) variation. This proves that the sharp modulation of the χ((2)) nonlinearity constitutes a sufficient condition for the emission of Čerenkov second harmonic in bulk materials. Our calculations are in excellent agreement with simple analytical approach utilizing the concept of reciprocal vectors representing the Fourier spectrum of the modulation of χ((2)).

Download full-text PDF

Source
http://dx.doi.org/10.1364/ol.37.003864DOI Listing

Publication Analysis

Top Keywords

modulation χ2
16
Čerenkov second-harmonic
8
second-harmonic generation
8
emission Čerenkov
8
χ2
5
role localized
4
modulation
4
localized modulation
4
χ2 Čerenkov
4
generation nonlinear
4

Similar Publications

Local Dipole Modulation Toward High Fill Factor in Organic Solar Cells.

Adv Mater

October 2024

State Key Laboratory of Polymer Physics and Chemistry, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.

Dipole moment arrangement in organic semiconductors plays a critical role in affecting the intermolecular packing, determining optoelectronic properties and device performance. Here, to get the desired fill factor (FF) values in organic solar cells (OSCs), the local dipole of non-fullerene acceptors (NFAs) is modulated by changing the molecular asymmetries. Two NFAs, AA-1 and AA-2 are designed and synthesized, which have different substitutions of alkyl and alkoxyl groups.

View Article and Find Full Text PDF

Artonin E (AA2) and artobiloxanthone (AA3) were extracted and purified from the acetone extract of the stem bark of (Parkinson) Fosberg. Preliminary investigations of both candidates revealed promising cytotoxic effects in oral cancer cells. Moreover, these candidates modulated the expression of pivotal proteins linked to oral cancer progression, eliciting apoptosis through caspase-3 and caspase-9 activation.

View Article and Find Full Text PDF

Tiron ameliorates acetic acid-induced colitis in rats: Role of TGF-β/EGFR/PI3K/NF-κB signaling pathway.

Int Immunopharmacol

February 2024

Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt. Electronic address:

Background: Ulcerative colitis (UC), an ongoing inflammatory disorder of the colon, is marked by persistent mucosal surface irritation extending from the rectum to the near-proximal colon. Tiron is a synthetic analogue of vitamin E which is known to have antioxidant and anti-inflammatory effects in various animal models, so the goal of this study was to find out whether Tiron had any preventive impacts on UC inflicted by acetic acid (A.A) exposure in rats.

View Article and Find Full Text PDF
Article Synopsis
  • The study presents an experimental demonstration of an optics-based half-adder that processes two channels of 4-phase-shift-keying (4-PSK) data using nonlinear wave mixing technology.
  • The system takes two sets of 4-ary phase-encoded inputs and produces corresponding outputs labeled as Sum and Carry through a nonlinear device, showcasing multiple phase levels for both inputs and outputs.
  • Experimental findings indicate that the half-adder achieves specific conversion efficiencies for data outputs, with low optical signal-to-noise ratio penalties at varying symbol rates, confirming its effectiveness in high-speed optical communication.
View Article and Find Full Text PDF

The transcriptomic response of two basidiomycete fungi to plant biomass is modulated by temperature to a different extent.

Microbiol Res

May 2023

Fungal Physiology, Westerdijk Fungal Biodiversity Institute, & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands.

Article Synopsis
  • Fungi have specific habitat preferences, and understanding their adaptation to different environments is crucial for biodiversity and industrial use.
  • Both Trametes pubescens and Phlebia centrifuga showcased different gene expressions based on the carbon sources (wheat straw and spruce) and growth temperatures (15°C and 25°C) they experienced.
  • The study found that T. pubescens exhibited more lignin and cellulose-related gene activity, while P. centrifuga showed a greater transcriptome response to temperature changes, indicating their different adaptations and molecular mechanisms in varying conditions.
View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!