High bandwidth frequency modulation of an external cavity diode laser using an intracavity lithium niobate electro-optic modulator as output coupler

We present a novel approach to high bandwidth laser frequency modulation. A lithium niobate chip is used as an intracavity electro-optic modulator in a tunable cateye external cavity diode laser. The modulator is conveniently integrated with the cateye output coupler, providing a unique approach to high bandwidth frequency stabilization and linewidth narrowing. The intracavity modulator feedback was successfully operated below one volt and achieved superior frequency noise suppression compared to conventional feedback through diode injection current modulation. A closed loop bandwidth of 1.8 MHz was demonstrated, and the laser linewidth reduced to around 1 Hz as measured by heterodyne measurement.S. Palmer, a, A. Boes, G. Ren, T. G. Nguyen, S. J. Tempone-Wiltshire, N. Longhurst, P. M. Farrell, A. Steiner, Ch. D. Marciniak, T. Monz, A. Mitchell, and R. E. Scholte

Dissolved Air Flotation (DAF) for Wastewater Treatment

© 2018 by Taylor & Francis Group, LLC. Flotation system consists of four major components-air supply, pressurizing pump, retention tank, and flotation chamber. The theory of dissolved air flotation (DAF) process is to separate suspended particles from liquids by bringing the particles to the surface of the liquid. In most cases, DAF is an alternative process to sedimentation and offers several advantages, including better final water quality, rapid startup, higher rates of operation, and thicker sludge. Additionally, DAF systems need less space compared with normal clarifiers, and due to their modular components, they allow easy installation and setup. This chapter covers types of flotation, process description of DAF, theory of DAF, advantages of DAF application in wastewater treatment, application of DAF process in wastewater treatment, and application of DAF in landfill leachate treatment

CO 2 Mitigation and Renewable Oil from Photosynthetic Microbes: A New Appraisal

biodiesel, bioenergy, bioengineering, biofuels, microalgae, microbes, mitigation, photobioreactor, photosynthesis,