Using ultra-short pulses to determine particle size and density distributions

We analyze the time dependent response of strongly scattering media (SSM) to ultra-short pulses of light. A random walk technique is used to model the optical scattering of ultra-short pulses of light propagating through media with random shapes and various packing densities. The pulse spreading was found to be strongly dependent on the average particle size, particle size distribution, and the packing fraction. We also show that the intensity as a function of time-delay can be used to analyze the particle size distribution and packing fraction of an optically thick sample independently of the presence of absorption features. Finally, we propose an all new way to measure the shape of ultra-short pulses that have propagated through a SSM.Comment: 15 pages, 29 figures, accepted for publication in Optics Express will update with full reference when it is availabl

From Laser Induced Line Narrowing To Electromagnetically Induced Transparency: Closed System Analysis

Laser induced line narrowing effect, discovered more than thirty years ago, can also be applied to recent studies in high resolution spectroscopy based on electromagnetically induced transparency. In this paper we first present a general form of the transmission width of electromagnetically induced transparency in a homogeneously broadened medium. We then analyze a Doppler broadened medium by using a Lorentzian function as the atomic velocity distribution. The dependence of the transmission linewidth on the driving field intensity is discussed and compared to the laser induced line narrowing effect. This dependence can be characterized by a parameter which can be regarded as ``the degree of optical pumping''.Comment: 8 pages, 5 figure

A gain-coefficient switched Alexandrite laser

We report on a gain-coefficient switched Alexandrite laser. An electro-optic modulator is used to switch between high and low gain states by making use of the polarization dependent gain of Alexandrite. In gain-coefficient switched mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a repetition rate of 5 Hz.Comment: 8 pages, 5 figure

Storage by trapping and spatial staggering of multiple interacting solitons in Λ\Lambda-type media

In this paper we investigate the properties of self induced transparency (SIT) solitons, propagating in a $\Lambda$-type medium. It was found that the interaction between SIT solitons can lead to trapping with their phase preserved in the ground state coherence of the medium. These phases can be altered in a systematic way by the application of appropriate light fields, such as additional SIT solitons. Furthermore, multiple independent SIT solitons can be made to propagate as bi-solitons through their mutual interaction with a separate light field. Finally, we demonstrate that control of the SIT soliton phase can be used to implement an optical exclusive-or gate.Comment: 7 pages, 7 figure

When Internationalization Funding Feels Tight: Satisfaction With Funding and Campus Internationalization Strategies

This study investigated predictors of satisfaction with an institution’s strategy for campus internationalization among international affairs staff (N = 1,520) and compared the varying perceptions of their institution’s funding to fulfill this mandate. This study identified factors that influenced these individuals’ sense of their institution’s internationalization strategy. Among international affairs staff who were most dissatisfied with their institution’s funding, satisfaction with how their institution managed the outsourcing of university functions, and perceived competition with other universities most influenced their perceptions of strategy. For those moderately satisfied with funding, retention of senior university leadership most influenced their perceptions of strategy. Support from senior administration, communication with faculty, and capacity to support increased student enrollment influenced perceptions of strategy for all respondents. The results of this study suggest the negotiation of the educational and entrepreneurial rationales for internationalization are far more complex—and dependent on far more factors—at institutions where international affairs staff perceive fewer human and financial resources to be available