Bi-directional laser breakthrough
Light is emitted from a quantum cascade laser when an electron falls from an excited energy level in a quantum well to a lower level. The quantum wells are defined by alternating layers of semiconduct...
Chemical physicist wins Nobel chemistry prize
Prior to Zewail’s work chemists had thought that chemical reactions occurred on the same time scale as molecular vibrations — that is, on the femtosecond scale. In the late 1980s, Zewail d...
Top quark and Bell’s inequalities top PhysicsWeb Nobel poll
Every year the Foundation asks 3000 physicists to nominate individuals for the prize, and compiles a short-list of 250 candidates. These names are then whittled down to a list of 30, from which the wi...
Blue lasers look up
Most semiconductor lasers emit light from the edge of the active laser region. However, in the VSCEL geometry light is emitted from the top of the device. This can reduce the threshold current needed ...
Read article: Top Livermore physicist resigns
Top Livermore physicist resigns
Campbell left his position last Friday after a series of anonymous faxes was sent to officials at the Department of Energy (DOE) saying that he did not have a doctorate degree. Although Campbell finis...
Dropping atoms gives precise value of g
Atomic interferometers use lasers to place atoms into superpositions of different quantum states. These states acquire different phases as they move in a gravitational field, and this phase difference...
Read article: A double-slit experiment in a single molecule
A double-slit experiment in a single molecule
Photons from the laser can excite electrons in the water molecules into a so-called anti-bonding state. Molecules in this state can adopt one of two distorted shapes, both of which can dissociate into...
Read article: Atom lasers
Atom lasers
The exotic quantum phenomenon of Bose–Einstein condensation is the key ingredient in a new type of laser that emits atoms rather than photons, and that promises to revolutionize atom optics
Vortex look for lasers
Scheuer and Orenstein used so-called vertical cavity surface-emitting lasers. In these devices the light is emitted from the top of the active region of the laser, rather than from the edge as in conv...
Light feels the heat and slows down
The researchers also showed that the rubidium gas, which they say is a “relatively easily created medium”, exhibits extremely efficient nonlinear interactions. Materials with such properti...
