M. L. Bhaumik

High‐power xenon fluoride laser

High‐power laser emission has been observed from xenon fluoride (XeF) at 351.1 and 353.1 nm. A peak laser power of 0.5 MW was obtained by using a mixture of Ar, Xe, and NF3 in the ratio of 250 : 25 : 1 at a total pressure of 1.7 atm. The laser gas was excited by a 1‐MeV 20‐kA electron beam for a pulse duration of 20 nsec. Energy deposited in the gas by the electron beam was estimated to be 1 J which gives a laser efficiency of 0.5%. Using a coaxial electron gun, an 80‐mJ 100‐nsec pulse was obtained with an efficiency of 3%.High‐power laser emission has been observed from xenon fluoride (XeF) at 351.1 and 353.1 nm. A peak laser power of 0.5 MW was obtained by using a mixture of Ar, Xe, and NF3 in the ratio of 250 : 25 : 1 at a total pressure of 1.7 atm. The laser gas was excited by a 1‐MeV 20‐kA electron beam for a pulse duration of 20 nsec. Energy deposited in the gas by the electron beam was estimated to be 1 J which gives a laser efficiency of 0.5%. Using a coaxial electron gun, an 80‐mJ 100‐nsec pulse was obtained with an efficiency of 3%.

High‐efficiency KrF excimer laser

Efficient high‐power laser emission has been observed at 249 nm from a KrF excimer laser obtained by an electron‐beam‐pumped mixture of Ar, Kr, and NF3 (1300:130:1) at a total pressure of 2.25 atm. An energy of 1.5 J was extracted in a 125‐nsec (FWHM) pulse from a 100‐cm3 volume, using a coaxial electron‐beam laser. Laser efficiency was estimated to be nearly 15% based on energy deposition in the gas. Over‐all electrical efficiency was ∼1%.

High‐power I2 laser in the 342‐nm band system

Strong laser emission was observed in the 342‐nm I2 band system from an e‐beam–excited mixture of Ar and CF3I (250 : 1) at a total pressure of 10 atm. Laser emission occurred simultaneously at 342.0, 342.3, 342.4, and 342.8 nm with a peak power of 3.6 MW in a 10‐nsec (FWHM) pulse.

Physics of Raman Lasers

The physics of Raman lasers is described in simple terms. A simplified gain formula is presented for the threshold of Raman-laser action. The features of stimulated Raman scattering are compared with those of spontaneous Raman process. Finally, a review of the various cavities used for Raman lasers is presented.

Deciphering the Enigma of Wave-Particle Duality

A reasonable explanation of the confounding wave-particle duality of matter is presented in terms of the reality of the wave nature of a particle. In this view a quantum particle is an objectively real wave packet consisting of irregular disturbances of underlying quantum fields. It travels holistically as a unit and thereby acts as a particle. Only the totality of the entire wave packet at any instance embodies all the conserved quantities, for example the energy-momentum, rest mass, and charge of the particle, and as such must be acquired all at once during detection. On this basis, many of the bizarre behaviors observed in the quantum domain, such as wave function collapse, the limitation of prediction to only a probability rather than a certainty, the apparent simultaneous existence of a particle in more than one place, and the inherent uncertainty can be adequately understood. The reality of comprehending the wave function as an amplitude distribution of irregular disturbances imposes the necessity of acquiring the wave function in its entirety for detection. This is evinced by the observed certainty of wave function collapse that supports the paradigm of reality of the wave function portrayed in this article.

Was Albert Einstein Wrong on Quantum Physics

Albert Einstein is considered by many physicists as the father of quantum physics in some sense. Yet there is an unshakable view that he was wrong on quantum physics. Although it may be a subject of considerable debate, the core of his allegedly wrong demurral was the insistence on finding an objective reality underlying the manifestly bizarre behavior of quantum objects. The uncanny wave-particle duality of a quantum particle is a prime example. In view of the latest developments, particularly in quantum field theory, the objections of Einstein are substantially corroborated. Careful investigation suggests that a travelling quantum particle is a holistic wave packet consisting of an assemblage of irregular disturbances in quantum fields. It acts as a particle because only the totality of all the disturbances in the wave packet yields the energy-momentum with the mass of a particle, along with its other conserved quantities such as charge and spin. Thus the wave function representing a particle is not just a fictitious mathematical construct but embodies a reality of nature as asserted by Einstein. Quanta 2015; 4: 35–42.

UNIFIED FIELD—THE UNIVERSAL BLUEPRINT?

The current status of the studies of the origin of the fundamental particles and the universe is presented. These studies indicate the unified field to be the source of both the fundamental particles and the universe itself. Furthermore, as a consequence of the unique properties of the quantum vacuum, the unified field is presumed to exist, in a quantum physical sense, everywhere in the very fabric of spacetime. In an analogy to the characteristics of the human genome, unified field appears to have the basic blueprint of at least everything physical in this universe.