Thermal expansion feedback for wave-front shaping

Model of thermal wave-front distortion in interferometric gravitational- wave detectors. I. Thermal focusing

We develop a steady-state analytical and numerical model of the optical response of power-recycled Fabry– Perot Michelson laser gravitational-wave detectors to nonlinear thermal focusing in optical substrates. We assume that the thermal distortions are small enough that we can represent all intracavity fields as linear combinations of basis functions derived from the eigenmodes of a Fabry–Perot...

The Conditions Shaping Nato’s Fifth Wave of Expansion

Wave-front design algorithm for shaping a quasi-far-field pattern.

To design a fully continuous wave-front distribution suitable for focused beam shaping by a deformable mirror, we modify the phase-retrieval algorithm by employing a uniformly distributed phase as a starting phase screen and spatial filtering for the near-field phase retrieved during the iteration process. A special phase unwrapping algorithm is not required to obtain a continuous phase distrib...

Thermal-wave balancing flow sensor with low-drift power feedback

A control system using a low-drift power-feedback signal was implemented applying thermal waves, giving a sensor output independent of resistance drift and thermo-electric offset voltages on interface wires. Kelvin-contact sensing and power control is used on heater resistors, thereby inhibiting the influence of heater resistance drift. The thermal waves are detected with a sensing resistor usi...

Wave-Shaping Surfaces

Controlling light has fascinated mankind since the dawn of civilization, and the centuries of studies leading to the development of modern optics can still be a great source of inspiration. The advent of metamaterials—artificial materials with unconventional properties built by assembling smaller-than-wavelength constituent elements—has opened new venues for the manipulation of light propagatio...