Phys.org March 18, 2022 An international team of researchers (China, USA – Arizona State University) generated structured transverse mode locking (TML) beams and second harmonic generation (SHG) beams by a sandwich-like microchip laser cavity that was passively Q-switched. They observed many rare SHG far-field beam patterns and their experiments showed good agreement with the simulations. It showed that parametric variation for the TML modes greatly changes the far-field beam patterns of the SHG beam. Generated SHG beam patterns vary with the propagation, and then they remain stable into the far field. The SHG beam patterns were observed to have more […]
Category Archives: Light
Discovery of ‘split’ photon provides a new way to see light
Nanowerk December 13, 2021 Bosons, such as photons, tend to bunch together unlike fermions. Thus it was natural for researchers to assume that splitting bosons would be an insurmountable task. According to a team of researchers in the US (Dartmouth College, SUNY Polytechnic Institute) the interplay between dynamical metastability and nontrivial bulk topology makes possible emergence of Majorana bosons. This leads to a distinctive form of topological metastability, whereby a conserved Majorana boson localized on one edge is paired, in general, with a symmetry generator localized on the opposite edge. They argue that Majorana bosons are robust against disorder and […]
‘Liquid’ light shows social behaviour
Phys.org October 7, 2021 Researchers in the Netherlands investigated the Bose-Einstein condensation of a photonic Bose gas in an environment with controlled dissipation and feedback. They created a micro-size mirror with channels in which photons flow like a liquid. They showed that by adjusting their frequency Bose-Einstein condensates naturally try to avoid particle loss and destructive interference in their environment. Their experiments revealed physical mechanisms involved in the formation of a Bose-Einstein condensate, which typically remain hidden when the system is close to thermal equilibrium. They demonstrated the effect even at room temperature. Their measurements offer a highly systematic picture […]
Microscopic metavehicles powered by nothing but light
Science Daily September 28, 2021 Optical tweezers were developed using a highly focused laser beam to control and maneuver tiny particles. An international team of researchers (Sweden, Russia) has shown that even unfocused light can be used to maneuver microscopic particles in a controlled manner by developing “metavehicle” consisting of a tiny particle coated with metasurface. They used the forces resulting from the light’s change in momentum control the meta-surface. By placing the metavehicle at on the bottom of the water dish, they used loosely focused laser to direct a plane wave of light onto them moving the metavehicle in […]
Physicists mix classical light with half a photon on a qubit
Phys.org August 31, 2021 An international team of researcher (Russia, UK) theoretically considered wave mixing under the irradiation of a single qubit by two photon fields. The first signal was a classical monochromatic drive, while the second one was a nonclassical light. They addressed two examples of a nonclassical light: (i) a broadband squeezed light and (ii) a periodically excited quantum superposition of Fock states with 0 and 1 photons. The mixing of classical and nonclassical photon fields gives rise to side peaks due to the elastic multiphoton scattering. They showed that a side peaks structure is distinct from the […]