we present a detailed analysis of the static tuning characteristics of three section tunable distributed bragg reflector (dbr) laser. the analysis is based on the transfer matrix method (tmm), transmission line and scattering theory. the key feature of the analysis is the use of modified oscillation condition. with the exact oscillation condition, the static tuning characteristics such as thres...

today, due to qualitative growth and scientific advances, energy, especially electricity is increasingly needed by human society. one of the almost endless and pure energy which have been paid attention over the years is the solar energy. solar cells directly convert solar energy into electrical energy and are one of the main blocks of photovoltaic systems. significant improvement has been made...

Firstand second-order Bragg reflectors at telecommunication wavelength (1.5 m) were fabricated in single-mode monolayer (As2S3) and multilayer (As-S-Se/As-S) chalcogenide glass (ChG) planar waveguides with near bandgap illumination using an interferometric technique. Reflectivities as high as 90% near 1555 nm, and index modulations up to 3 10 4 were achieved. The volume photodarkening effect is...

The article proposes a modified Design-Based Research (DBR) framework which accommodates the various socio-cultural factors that emerged in the longitudinal PA-HELP research study at Central University College (CUC) in Ghana, Africa. A transnational team of stakeholders from Ghana, Canada, and the USA collaborated on the development, implementation, and subsequent modification of the DBR framew...

Design Based Research (DBR) is a new and still-emerging approach to research about design, learning, and allied areas. This article reports one designer’s experiences within a DBR project. Whereas most reports of DBR focus on the outcomes of the design itself, the current paper offers a hermeneutical perspective by focusing on the personal narrative of the designer. Using Edelson’s (2002) categ...

We have successfully prepared anodized alumina membrane distributed Bragg reflector (DBR) using electrochemical anodization method. The transmission peak of this distributed Bragg reflector could be easily and effectively modulated to cover almost any wavelength range of the whole visible spectrum by adjusting anodization temperature.

Dual reflector antennas are considered as pencil beam antennas that can produce radiation identical to searchlight. Cassegrain Reflector Antenna Design consists of various effects caused by blockage by primary feed or by the subreflector and its effect on overall performance. The objective of the paper is to provide the overview of the designing approach that is used to design the axially symme...

1 This research was sponsored by NSF Grant 9704015, a grant from the UC Micro Program, and the Hewlett-Packard Corporation External Grants program. Abstract This paper evaluates the Dynamic Boundary Restricted protocol with phase-checking (DBRpc). DBRpc is a highly-adaptable extension of DBR that can respond to changes in the network environment and application workload. DBRpc is suitable for r...