Three-Level Laser Dynamics with the Atoms Pumped by Electron Bombardment

We analyze the quantum properties of the light generated by a three-level laser with a closed cavity and coupled to a vacuum reservoir. The three-level atoms available in the cavity are pumped from the bottom to the top level by means of electron bombardment and we carry out our analysis by putting the noise operators associated with the vacuum reservoir in normal order. The maximum quadrature squeezing of the light generated by the laser, operating far below threshold, is found to be 50% below the coherent-state level. We have also established that the quadrature squeezing of the output light is equal to that of the cavity light and has the same value in any frequency interval. This implies that the quadrature squeezing of the laser light is an intrinsic property of the individual photons.Comment: 14 pages, 1 figure; a revised version of arXiv: 1105.1438v

Two-Level Laser Dynamics with a Noiseless Vacuum Reservoir

We analyze the quantum properties of the light generated by a two-level laser in which the two-level atoms available in a closed cavity are pumped to the upper level by means of electron bombardment. We consider the case in which the two-level laser is coupled to a vacuum reservoir via a single-port mirror and seek to carry out our analysis by putting the noise operators associated with the vacuum reservoir in normal order. It is found that the two-level laser generates coherent light when operating well above threshold and chaotic light when operating at threshold. Moreover, we have established that a large part of the total mean photon number is confined in a relatively small frequency interval.Comment: 11 pages, 1 figure; this is a revised version of a paper published in Opt. Commun. (284, 1357, 2011). arXiv admin note: text overlap with arXiv:1105.143

Interaction of a two-level atom with squeezed light

We consider a degenerate parametric oscillator whose cavity contains a two-level atom. Applying the Heisenberg and quantum Langevin equations, we calculate in the bad-cavity limit the mean photon number, the quadrature variance, and the power spectrum for the cavity mode in general and for the signal light and fluorescent light in particular. We also obtain the normalized second-order correlation function for the fluorescent light. We find that the presence of the two-level atom leads to a decrease in the degree of squeezing of the signal light. It so turns out that the fluorescent light is in a squeezed state and the power spectrum consists of a single peak only.Comment: 9 pages and 9 figures, in press, Opt. Commu

Superposed Coherent and Squeezed Light

We first calculate the mean photon number and quadrature variance of superposed coherent and squeezed light, following a procedure of analysis based on combining the Hamiltonians and using the usual definition for the quadrature variance of superposed light beams. This procedure of analysis leads to physically unjustifiable mean photon number of the coherent light and quadrature variance of the superposed light. We then determine both of these properties employing a procedure of analysis based on superposing the Q functions and applying a slightly modified definition for the quadrature variance of a pair of superposed light beams. We find the expected mean photon number of the coherent light and the quadrature variance of the superposed light. Moreover, the quadrature squeezing of the superposed output light turns out to be equal to that of the superposed cavity light.Comment: 7 page

…And There Was Light. On Becoming a Writer: A Reflective Journey

This paper chronicles my development as a multicultural picture book writer, with a manuscript as an illustration of this process. I see myself emerging from within since joining the Critical and Creative Thinking Program. My journey actually started a few years before enrolling in the program. As an adult, I wanted to explore my life-long fascination with books, and to discover if I could write a book of my own. Using the various CCT coursework, I was able to peel off the many layers of obstacles that prevented me from realizing my dream. Using the power of reflective thinking, I learned which skills I already had and which skills I needed to cultivate. The next obvious step was to self-evaluate my skills as a writer using a second language. Since I already had a background of high school English when I moved to the United States, I decided to focus the writing process on writing for children in English. Many CCT tools became very useful to me, yet one of the most important tools I gained was the knowledge and skill to reflect on my writing and to think metacognitively. This introspective thinking and the acceptance of taking risks allowed me to examine the obstacles to my writing process, and more specifically, why I frequently was not writing. In every instance that I evaluated my writing, the only question that came up was the question of how I could improve my fundamental writing skills in English. Once I felt that I addressed the ‘how’, I thought the road to success was around the corner. Yet I still found myself very far away from ‘success.’ I had predefined ‘success’ to mean having my written work published. Throughout my journey this predefined criteria had become an invisible internal barrier. The question of why I was not ‘making it’ I left unanswered because I feared the answer. I was also afraid of discovering the cause of my insecurities because I thought it could mean the end of my dream. At the end of my CCT journey, I wrote a multicultural picture book. This paper is a metacognitive chronicle juxtaposed with excerpts from my manuscript

Mobile Genetic Elements and Natural Gene Transfer in Rumen Microbial Ecosystem

As technology is going be modern different changes that occur in the nature become studied. Rumen microbes especially rumen bacteria play a vital role in utilization of ruminants feed. Without rumen microbe’s rumen can’t function correctly. So, when we feed our animals, we are also feeding rumen microbes which convert the plant fiber to VFA which used by ruminants as an energy source for maintenance and production. Through the process these microbes change in their genetic structure and function because of natural gene transfer which is mediated by movable genetic elements like bacteriophage, plasmid, transposons and other segments. In this review prokaryotes which include bacteria and archae have got large cover than eukaryotes because most significant changes in rumen are carried by those organisms. HGT is the way to perform this function because it enables bacteria to respond and adapt to their environment much more rapidly by acquiring large DNA sequence from other bacterium in a single transfer and mechanisms of bacterial gene transfer include transformation, transduction and conjugation.  So this event has an impact on the microbe themselves, for the rumen ecosystem, the animal and the environment where these changes are related. These changes include antibiotic resistance, better conversion of feeds and effects in methane and ammonia production. Keywords: Horizontal Gene Transfer, Prokaryotes, Rumen. Rumen Microbes DOI: 10.7176/ALST/78-03 Publication date: February 29th 202

A degenerate three-level laser with a parametric amplifier

The aim of this paper is to study the squeezing and statistical properties of the light produced by a degenerate three-level laser whose cavity contains a degenerate parametric amplifier. In this quantum optical system the top and bottom levels of the three-level atoms injected into the laser cavity are coupled by the pump mode emerging from the parametric amplifier. For a linear gain coefficient of 100 and for a cavity damping constant of 0.8, the maximum intracavity squeezing is found at steady state and at threshold to be 93%.Comment: 8 pages, 4 figures, published versio