Related Experiment Video

Updated: Jun 22, 2026

Demonstration of Spin-Multiplexed and Direction-Multiplexed All-Dielectric Visible Metaholograms
08:48

Demonstration of Spin-Multiplexed and Direction-Multiplexed All-Dielectric Visible Metaholograms

Published on: September 25, 2020

Orthogonal polarization dual-channel holographic memory in cationic ring-opening photopolymer

Haoyun Wei, Liangcai Cao, Zhenfeng Xu

    Optics Express
    |June 12, 2009
    PubMed

    More Related Videos

    Gradient Echo Quantum Memory in Warm Atomic Vapor10:00

    Gradient Echo Quantum Memory in Warm Atomic Vapor

    Published on: November 11, 2013

    A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference07:56

    A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference

    Published on: September 5, 2019

    Related Concept Videos

    Photochemical Electrocyclic Reactions: Stereochemistry01:26

    Photochemical Electrocyclic Reactions: Stereochemistry

    The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
    Selection Rules: Photochemical Activation
    Thermal Electrocyclic Reactions: Stereochemistry01:17

    Thermal Electrocyclic Reactions: Stereochemistry

    The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
    Selection Rules: Thermal Activation
    Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
    Cationic Chain-Growth Polymerization: Mechanism00:57

    Cationic Chain-Growth Polymerization: Mechanism

    The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the generated carbocation,...
    Thermal and Photochemical Electrocyclic Reactions: Overview01:26

    Thermal and Photochemical Electrocyclic Reactions: Overview

    Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
    Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)01:16

    Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)

    Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
    Dielectric Polarization in a Capacitor01:31

    Dielectric Polarization in a Capacitor

    The presence of a dielectric medium in a capacitor not only changes the voltage and capacitance but also affects the electric field. In general, dielectrics can be of two types: polar and nonpolar. In a polar dielectric, the positive and negative charges in the molecules are separated by a distance and hence have a permanent dipole moment. In contrast, no such charge separation exists in a nonpolar dielectric, however the nonpolar molecules get polarized in the presence of an external electric...