New energy-transfer upconversion process in Er(3+):ZBLAN mid-infrared fiber lasers

Abstract not availableOri Henderson-Sapir, Jesper Munch, and David J. Ottawa

An all-optical trap for a gram-scale mirror

We report on a stable optical trap suitable for a macroscopic mirror, wherein the dynamics of the mirror are fully dominated by radiation pressure. The technique employs two frequency-offset laser fields to simultaneously create a stiff optical restoring force and a viscous optical damping force. We show how these forces may be used to optically trap a free mass without introducing thermal noise; and we demonstrate the technique experimentally with a 1 gram mirror. The observed optical spring has an inferred Young's modulus of 1.2 TPa, 20% stiffer than diamond. The trap is intrinsically cold and reaches an effective temperature of 0.8 K, limited by technical noise in our apparatus.Comment: Major revision. Replacement is version that appears in Phy. Rev. Lett. 98, 150802 (2007

Compact cavity-dumped Q-switched Er: YAG laser

Published 13 September 2016Abstract not availableLachlan Harris, Myles Clark, Peter Veitch, and David Ottawa

Measurement of radiation-pressure-induced optomechanical dynamics in a suspended Fabry-Perot cavity

We report on experimental observation of radiation-pressure induced effects in a high-power optical cavity. These effects play an important role in next generation gravitational wave (GW) detectors, as well as in quantum non-demolition (QND) interferometers. We measure the properties of an optical spring, created by coupling of an intense laser field to the pendulum mode of a suspended mirror; and also the parametric instability (PI) that arises from the nonlinear coupling between acoustic modes of the cavity mirrors and the cavity optical mode. Specifically, we measure an optical rigidity of $K = 3 \times 10^4$ N/m, and PI value $R = 3$.Comment: 4 pages, 3 figure

The development of religious drama in England in the twentieth century

The aim of this thesis is to trace the history, and examine the artistic achievement, of the modern revival of religious drama. The thesis is divided into four sections. In Section One, the nature of religious drama is defined, and the definition supported by a brief examination of some plays which are of that kind. Section Two is concerned with the revival itself. In Chapter One, an attempt is made to account for it: the reconciliation of Church and Stage in England in the late nineteenth century, the interest shewn in England during that period in the passion Play of Oberammergau, and some 'religious' tendencies apparent in the London theatre at the turn of the century, are considered. in Chapter Two, the history of the revival is traced, from 1871-1952. Section Three is devoted to a critical examination of the most important religious plays written during the period of the revival. Special attention is paid to the work of the last thirty years. The plays are classified, for the purpose of critical discussion, under three headings - Bible Drama, the Church and the Saints, Plays of Modern Life - and are considered in relation to the definition established above. In Section Four, the achievement of this body of work is summed up, and its value assessed. The conclusion reached is that although few of the individual plays achieve artistic excellence, the religious impulse has given modern drama a new vitality. An appendix giving the dates of publication and first performance of the plays considered in Section Three is added, together with a short book-list

Versatile and widely tunable mid-infrared erbium doped ZBLAN fiber laser

We report on a long wavelength emitting rare earth doped fiber laser with emission centered at 3.5 {\mu}m and tunable across 450 nm. The longest wavelength emission was 3.78 {\mu}m, which is the longest emission from a fiber laser operating at room temperature. In a simple optical arrangement employing dielectric mirrors for feedback, the laser was capable of emitting 1.45 W of near diffraction limited output power at 3.47 {\mu}m. These emission characteristics compliment the emission from quantum cascade lasers and demonstrate how all infrared dual wavelength pumping can be used to access high lying rare earth ion transitions that have previously relied on visible wavelength pumping

Recent results of a seismically isolated optical table prototype designed for advanced LIGO

The Horizontal Access Module Seismic Attenuation System (HAM-SAS) is a mechanical device expressly designed to isolate a multipurpose optical table and fit in the tight space of the LIGO HAM Ultra-High-Vacuum chamber. Seismic attenuation in the detectors' sensitivity frequency band is achieved with state of the art passive mechanical attenuators. These devices should provide an attenuation factor of about 70dB above 10Hz at the suspension point of the Advanced LIGO triple pendulum suspension. Automatic control techniques are used to position the optical table and damp rigid body modes. Here, we report the main results obtained from the full scale prototype installed at the MIT LIGO Advanced System Test Interferometer (LASTI) facility. Seismic attenuation performance, control strategies, improvements and limitations are also discussed

Stabilization of injection-locked lasers using spatial mode interference

We report the use of spatial-mode-interference, or tilt-locking, for the active stabilization of injection-locking of a Nd:YAG laser. We show that this control scheme is robust and adds negligible frequency noise to the injection-locked laserOttaway, D.J.; Gray, M.B.; Shaddock, D.A.; Hollitt, C.; Veitch, P.J.; Munch, J.; McClelland, David Ernes

Power scalable TEM(oo) CW Nd: YAG laser with thermal lens compensation

We present finite-element analyzes and experimental results to validate our approach for building high-power single-mode Nd:YAG lasers. We show that the thermooptical and thermomechanical properties of a slab laser can be controlled. This is essential for the use of the proposed unstable resonator. We include demonstration of an efficient subscale laser operating at 20 W TEM00.D. Mudge, M. Ostermeyer, P. J. Veitch, J. Munch, B. Middlemiss, D. J. Ottaway and M. W. Hamilto

Short-pulse actively Q-switched Er:YAG lasers

Published 28 Jun 2016Abstract not availableDavid J Ottaway, Lachlan Harris, and Peter J. Veitc