A diode-pumped Yb:YCOB laser at 1086 nm is passively Q switched by using InGaAs quantum wells as saturable absorbers and utilizing the Bragg mirror structure as an output coupler. With an absorbed pump power of 9.2 W the laser produces pulses of 100 ms duration with average pulse energy of as much as 165 microJ at a pulse repetition rate of 7 kHz.

Although much thinner than conventional optical interference coatings, nanometer-thick films made of optically absorbing materials can display strong interference effects. This new class of coatings shows promise for coloring and labeling, optical filters, tunable absorbers and emitters, and energy harvesting.

Using metamaterial absorbers, we have shown that metallic layers in the absorbers do not necessarily constitute undesired resistive heating problem for photovoltaics. Tailoring the geometric skin depth of metals and employing the natural bulk absorbance characteristics of the semiconductors in those absorbers can enable the exchange of undesired resistive losses with the useful optical absorban...

We report on the dynamics of photodegradation and subsequent recovery of two-photon fluorescence in a dye-doped polymer. The energy dependence suggests that photodegradation is a linear process, while recovery is entropic. Such recovery could be useful to high-intensity devices such as two-photon absorbers, which can be used in many applications.

In this article, the results of a study on energy absorption characteristics of foam-filled thin-walled structures with finite element analysis have been presented. Four specimens of thin walled structures have been filled with uniform foam and three specimens have been filled with linear four-layered foam. Also, eight layers HLH (High-Low-High) and eight layers LHL (Low-High-Low) have been sim...

We analyzed the physical basics for design of absorbers for high energy beams of electrons and photons. Typical examples are the collimators and dump systems. In particular, we considered a collimator for usage in Cornell ERL project, where it could be used for reduction of γ , − e halo, minimization of exposure SRF module to SR from neighboring bending magnet and for absorption of direct beam ...

This paper describes how an inerter-based device for structural vibration suppression can be realized using an electromagnetic transducer such as a linear motor. When the motor shaft moves, a difference of voltage is generated across the transducer coil. The voltage difference is proportional to the relative velocity between its two terminals. The electromagnetic transducer will exert a force p...

Thermal emission plays a critical role in a wide variety of applications, including adjusting radiative losses in photovoltaics and selective solar absorbers, as well as enhancing the emission of high energy photons for thermophotovoltaics and photon-enhanced thermionic emission. In this work, we consider the benefit to thermal emission associated with replacing conventional mirrors with meta-m...

A task was initiated to improve the energy absorption capability of an existing aircraft seat through costeffective retrofitting, while keeping seat-weight increase to a minimum. This task was undertaken as an extension of NASA ongoing safety research and commitment to general aviation customer needs. Only vertical crash scenarios have been considered in this task which required the energy abso...

We present results from Keck HIRES, KPNO 4m/RC Spec and HST FOS spectra of a low-redshift, close QSO pair and a close, higher-redshift QSO triplet in order to explore the size evolution, shape and clustering of Ly α absorbers. The results we highlight here indicate that there is no strong evidence for evolution of Ly α cloud size with redshift, that strong (Wo > 0.4Å) Ly α forest absorbers are ...