Unmasking the optical counterpart to the ultraluminous X-ray source, NGC 5204 X-1

Unruh effect in a waveguide

Unstable Optical Resonators & Fractal Light

Untwinkling the stars -- Part 2

Untwinkling the stars--Part 1

Unusual Resonators: Plasmonics, Metamaterials, and Random Media

Unveiling the Hearts of (U)LIRGs with Laser Guide Star Adaptive Optics

Unveiling the Young Central Stellar Disk in the Advanced Luminous Infrared Galaxy Arp 193

Unveiling Uranus' Clouds: New Observations From Gemini-North NIFS And NIRI

Upconversion channels in Er3+:ZBLALiP: multicolour microspherical light source

Update of the AFGL atmospheric absorption line parameters compilation

Update on optical design of adaptive optics system at Lick Observatory

Update on the TMT adaptive optics real time controller

Update on the TMT laser guide star facility design

Update on the Wide-Field Infrared Survey Explorer (WISE)

Upgrade of a large millimeter-wavelength radio telescope for improved performance at 115 GHz.

Upgrade Of The SDSS Spectrographs For BOSS

Upgrade on 61-element adaptive optical system for 1.2-m telescope of Yunnan Observatory

Upgrade plans for the Subaru AO system

Upgraded hard x-ray telescope with multilayer supermirror for the InFOCµS balloon experiment