We describe erbium-ytterbium co-doped fiber lasers in different free-running and tunable configurations. The lasers were cladding-pumped by high-power multimode diode sources. We compare pumping at 915 and 980 nm. With a free-running laser, we obtained slope efficiencies of up to 50% with 915-nm pumping and 38% with 980-nm pumping, with respect to absorbed pump power. We reached a double-ended ...

First demonstration of cross phase modulation based interferometric switch is presented in silicon on insulator waveguides. By using Mach-Zehnder interferometric configuration we experimentally demonstrate switching of CW signal ~25 nm away from the pump laser. We present the effect of free carrier accumulation on switching. Additionally, we theoretically analyze the transient effects and degra...

The current work investigates the exergy analysis of a new system to generate power, heat, and refrigeration. In the proposed system, the heat loss of a gas turbine (GT) is first recovered by a Heat Recovery Steam Generator (HRSD), then by an Organic Rankine Cycle (ORC) to generate warm water and additional power, respectively. In the ORC, reheating is used to increase the output power, the req...

It is well known that quantum coherence and interference are important mechanisms in tailoring optical properties of atoms and molecules. Examples are the enhancement of the index of refraction, large optical Kerr nonlinearities, and the cancellation of absorption. Nonlinear media provide a variety of new applications, such as ultra-slowing of light propagation, superluminal light propagation, ...

Ocean wave is one of the renewable energy resources that these days various devices are used to extract its energy. Oscillating Water Column (OWC) installed on the shore is one of the wave energy absorption systems which has received attention due to its simple structure. Investigation of the pneumatic power is of great importance in such systems as the conversion of wave energy to pneumatic en...

We present a study of the terahertz (Tilz) generation by optical rectification in a 2 mm thick <110> ZnTe crystal. The conditions for the most efficient THz generation are described. We investigate the competition between optical rectification (OR), second harmonic generation (SHG), two photon absorption (TPA) and free-carrier absorption in the diffraction limit, for excitation spot sizes small...

Two commercial photodiodes are tested for two-photon absorption at 520 nm. The results indicate strong linear absorption and negligible two-photon absorption at current power level. Two major types of error associated with autocorrelation measurement based on two-photon induced photocurrent were identified and investigated. Computer simulations show linear absorption can significantly distort t...

Nonlinear loss is the central problem in silicon devices that operate using nonlinear optical effects. Wavelength converters are one example of such devices, wherein high optical intensities required for nonlinear interactions cause two-photon absorption and severe free-carrier absorption. In this paper, we report the first demonstration of nonlinear photovoltaic effect in silicon wavelength co...

Diode-laser absorption tomography is described with which the spatial temperature and the atomic number density distribution of a 3-kW class arcjet can be derived simultaneously by reconstruction of the absorption coefficient field of the arcjet's argon exhaust plume. One can perform various parameter measurements by changing the arcjet's mass-flow rates and discharge currents. The maximum temp...