In the present paper, the problem of multi-pumping all Raman amplifier has been investigated to obtain a maximum flatness gain and increases the bandwidth of the cascaded Raman amplifiers over a wide range of optical signal wavelengths for long-haul ultra-wide wavelength division multiplexing (UW-WDM) transmission systems due to multi-pumping wavelengths and pumping power . Three cases are anal...

Fibre Raman amplifiers are being deployed in many new long-haul and ultra long-haul fibre-optic transmission systems, making them the first and most widely commercialized nonlinear optical devices in telecommunications. One of the main reasons for this is their improved noise figure and reduced nonlinear penalty of fibre systems hence allowing for longer amplifier spans. In this paper, we have ...

We demonstrate a method for generating flow within a microfluidic channel using an optically driven pump. The pump consists of two counter rotating birefringent vaterite particles trapped within a microfluidic channel and driven using optical tweezers. The transfer of spin angular momentum from a circularly polarised laser beam rotates the particles at up to 10 Hz. We show that the pump is able...

In this seminar we present the structure, operating regime and use of solid state laser with passive Qswitch. We give a description and comparison of two basic concepts of optical pumping, the lamp pumping and the diode pumping. Finally we present the Q-switch theory and more precisely passive Q-switch theory.

We report on an order of magnitude enhanced nonlinear response of vanadium dioxide thin film patterned with nanoresonators--nano slot antennas fabricated on the gold film. Transmission of terahertz radiation, little affected by an optical pumping for the case of bulk thin film, can now be completely switched-off: DeltaT/T approximately -0.9999 by the same optical pumping power. This unprecedent...

We have grown crystals of solid argon doped with rubidium atoms. The spectrum of the implanted atoms depends on the crystal-growth temperature and annealing history. We have used optical pumping to polarize the spin state of the implanted atoms and polarization spectroscopy to detect the spin state and measure the spin-relaxation time. In addition to the desired optical pumping, we also observe...

The standard model of Spin-Exchange Optical Pumping of He has come under close scrutiny as researchers try to maximize the quantity and polarization of He. This paper will review four important effects that have come to light: 1) pumping with frequency narrowed diode lasers significantly improves the polarization and production rate as compared to off-theshelf broadband sources 2) Rb-K mixtures...

We study the conditions for operation of the 22 GHz ortho-water maser in a dusty medium near late-type stars. The main physical processes, such as exchange of energy between dust and gas in the radiation field of a star, radiative cooling by water molecules and pumping of water masers are described self-consistently. We show that the presence of dust grains of various types (or of one type with...

A general analytic solution for Brillouin distributed sensing in optical fibers with sub-meter spatial resolution is obtained by solving the acoustical-optical coupled wave equations by a perturbation method. The Brillouin interaction of a triad of square pump pulses with a continuous signal is described, covering a wide range of pumping schemes. The model predicts how the acoustic wave, the si...